Sir Alfred Hitchock, 80, the British-born director who for 50 years frightened and delighted movie audiences with thrillers that set screen standards for terror and suspense, died Tuesday morning at his home in Los Angeles.

Although the cause of death was not immediately announced, Mr. Hitchcock had a heart pacemaker and had been suffering from both kidney failure and arthritis.

Mr. Hitchcock had used a wheelchair in recent years and had gone through several days of diagnostic tests at Cedar Sinai Hospital Medical Center early last month.

A hospital spokesman said at the time that Mr. Hitchcock "just didn't feel good," and added that the health problems then were not considered serious.

No movie director in the history of film was more popular with audiences, more consistently successful at the box office nor more prankishly public a figure than Alfred Joseph Hitchcock, whose name was more prominently displayed than those of the stars on most of the films he made.

Mr. Hitchcock became a genre unto himself, commonly known as "the master of suspense," and an unchallenged whiz at manipulating movie and television audiences with tales of fear and mystery. Film critic Pauline Kael has said of him, "A pretty good case could be made for Alfred Hitchcock as the master entertainer of the movie medium."

Yesterday, some of the actors who appeared in some of Mr. Hitchcock's 53 films both mourned and praised him. "There was nobody like him, and he'll be very hard to replace," said James Stewart, the pursued and beleaguered Hitchcock hero of "Rear Window," "Vertigo" and "The Man Who Knew Too Much."

"I've lost a wonderful friend," Stewart said. "The world has lost a tremendous contribution to the art of film and to millions and millions of people."

Janet Leigh, the actress who played the victim of the most famous murder in screen history -- the shower stabbing in "Psycho" -- called Mr. Hitchcock "a master of his profession," and Anthony Perkins, who played the psycho with the knife, recalled of Mr. Hitchcock that "He always executed his suspense with taste; he never offended you. You were scared by it, but pleasantly."

Henry Ford, who played the title role in "The Wrong Man," said "I think his humor was the most unique thing about him. He was one of our giants. I feel very fortunate to have worked with him. He was a totally delightful man."

Last night, the White House issued a statement from President Carter in which he called the director's death "an almost personal loss to all of us who love the movies." The statement noted Mr. Hitchcock's many contributions to the art of film making, then went on to say that ". . . more than a little Alfred Hitchcock will appear in every thriller, every urbane mystery and every well-wrought shocker that is made for decades to come."

The director who spent a half century wittily scaring the wits out of moviegoers with films such as "Strangers on A Train," "Frenzy," "The Birds" and "Dial M for Murder," always professed he was himself meek, docile and harmless. "Everything frightens me," he once remarked.

Mr. Hitchcock not only turned himself into a droll figure of fun to publicize his film -- he made cameo appearances in most of them, always looking a bit like a bemused mortician out of Dickens or Charles Addams -- but also became a national television star in the '50s when he hosted the weekly series "Alfred Hitchcock Presents."

Each program opened with the director's famous curley-que outline sketch of his portly silhouette accompanied by Gounod's whimsical music "Funeral March of a Marionette" and followed by Mr. Hitchcock himself, who delivered unto viewers a mock funereal "Good evening."

Mr. Hitchcock noted, years later, that he chose the musical theme himself. "I'm the marionette, you see, that's the whole point of it," he said. The series ran as a weekly half-hour from 1955 to 1962 and became "The Alfred Hitchcock Hour" from 1962 to 65. Reruns are in syndication throughout the world.

Many of Mr. Hitchcock's films dealt with the murky, amoral world of modern espionage -- films such as "Notorious," "North By Northwest," "Saboteur," "The 39 Steps" and the planned film that was to be his 54th production "The Short Night," to be based on the career of British double agent George Blake. The film was in preparation at the time of Mr. Hitchcock's death.

Although long a favorite with movie audiences who knew to expect a virtual roller coaster ride from the best of his movies, Mr. Hitchcock found favor with higher-brow movie critics only in more recent years, when his work was re-analyzed and found to be not only amusing and masterful but also occasionally profound. Among Mr. Hitchcock's favorite themes was that of the average citizen suddenly and unwittingly capapulated into extraordinary situations over which he had no control.

The plights of the leading characters in films like "North by Northwest" and "The Man Who Knew Too Much" have been said to symbolize the pecularily disoriented and imperiled state of 20th century man.

Although the first film Mr. Hitchcock made after moving to the United States in 1940, "Rebecca," won the Osca as best picture of the year, Mr. Hitchcock himself never won a best director's Academy Award. Honors were plentiful during his career, however. In 1968, the Motion Picture Academy voted him the Irving G. Thalberg Memorial Award for his contributions to movie making.

In 1971, Mr. Hitchcock was awarded the French Legion of Honor and, in presenting the award, French Film Society Secretary Henri Langlois also made him an honorary Frenchman because, he told Mr. Hitchcock, "You know how to drink well and eat well."

In 1974, Mr. Hitchcock was honored with a star studded tribute sponsored by the Film Society of Lincoln Center in New York. Among those attending was Princess Grace of Monaco who, as Grace Kelly, stabbed a potential killer to death with a pair of scissors in "Dial M for Murder."

After that scene and many other involving sudden death was screened for the audience, and Mr. Hitchcock was rewarded with a prolonged and vociferous standing ovation, his only comment to the crowd was typically mordant and cryptic: "I still think the scissors was the best way."

Earlier, and unbenownst to him, he was paid perhaps the ultimate backbanded compliment by a women in the 15th row who said to her husband, as Janet Leigh was stepping into the shower again on the silver screen, "Tell me when it's over."

In 1979, Mr. Hitchcock became the seventh recipient of the American Film Institute's annual Life Achievement Award, which he mischievously referred to in his acceptance speech as the "Life Amusement Award." In the same speech, however, he also paid touching tribute to his wife, Alma Reville, with whom he had lived and worked since 1926.

"I share this award, as I have my life, with her," said Mr. Hitchcock, as Mrs. Hitchcock, partially paralyzed by two strokes, sat tearfully at his side on the dais.

On Dec. 31, 1979, Mr. Hitchcock was named Knight Commander of the Order in the British Empire by Queen Elizabeth II. Mr. Hitchcock, now a naturalized American citizen, had planned to visit England for the official knighting ceremony this year.

Throughout his career, Mr. Hitchcock delighted in using the volatile capabilities of film to excite, surprise and manipulate an audience. In a landmark book-length interview with French director Francois truffaut, an ardent Hitchcock admirer, Mr. Hitchcock spoke fondly of "playing the audience like an organ" in order to get the desired responses.

At the AFI dinner, Truffaut said of Mr. Hitchcock, "In America you respect him for shooting scenes of love like scenes of murder, while in France we respect him for shooting scenes of murder like love." Truffaut was one of several filmmakers who made films in open homage to Mr. Hitchcock. In Truffaut's case it was "The Bride Wore Black."

Other films of pure Hitchcock homage including Brain De Palma's "Obsession" and "Sisters" (replicas of "vertigo"and "Psycho" respectively), Jonathan Demme's "The Last Embrace and the affectionate Mel Brooks satire "High Anxiety." Currently a third version of the "The 39 Steps" is in release but it is not unlikely that Mr. Hitchcock's original will remain the definitive movie.

Born to a London poultry dealer and his wife on August 13, 1899, Mr. Hitchcock attended a Jesuit boarding school in his youth, which he and film critics later would say contributed to the sensibility that ran through his films. Mr. Hitchock frequently would repeat in later years an incident that he said shaped his thinking.

Punished for a childhood offense by his father, the young Alfred was sent to the local jail with a note explaining his crime to the officer. The sergeant, a friend of the boy's father locked the 5-year-old in a cell for a few minutes and then admonished him with, "That's what we do with naughty little boys."

Mr. Hitchcock would say later that this incident engendered a life-long fear of police and, implicitly, of all official authority. "I wouldn't drive a car for 11 years after I came to this country for fear of getting a ticket," he told an American interviewer in 1956.

A career in engineering was side-tracked when Mr. Hitchcock enrolled in a fine arts course at London University and later became enamored of the cinema. His earliest work in films was at the prestigious UFA studios in Munich, where his experience as an art director helped develop his keen visual sense.

His third film, and the first he directed in England, began his tradition of suspense thrillers: "The Lodger." It was also the first film in which Mr. Hitchcock made a cameo appearance but out of economy rather than playfullness; he couldn't afford enough extras for the film so he became one himself.

In later years he would commit to film some of the medium's most unforgettable and penetrating imagery -- from the crop-dusting airplane's assault on a panicked Cary Grant in "North by Northwest" to the stylized shower assault in "Psycho" to the dangling of a villain from the torch of the Statue of Liberty in "Saboteur" to the murder's flight under a camouflage of umbrellas in "Foreign Correspondent" to the murderous runaway merry-go-round of "Strangers on A Train."

The man who played and toyed with death in film after film seldom spoke seriously about the subject in interviews. In 1969, he told one reporter, "I want to be remembered as a man who entertained millions through the technique of film. I'm satisfied with my life, and what the years have brought me. I wouldn't dream of retiring; the figure of a birthday is something one ignores."

In a 1973 interview for public television, Mr. Hitchcock said, "I'm pretty well a loner. I don't get involved with conflicts; I don't see the point of it. . . I think somebody once said to me, 'What's your idea of happiness?' and I said, 'A clear horizon. No clouds, no shadows, nothing.'"

In addition to his wife, Mr. Hitchcock is survived by a daughter, Patricia O'Connell, and three grandchildren.