Merle Miller, 67, an author best known for his deft and effective use of oral history to write best-selling biographies of Presidents Lyndon B. Johnson and Harry S Truman, died yesterday of complications after the removal of his appendix at Danbury Hospital in Danbury, Conn.

Mr. Miller was also the author of eight novels. In 1971, in the early stages of the homosexual rights movement, he attracted wide attention for an article he wrote in The New York Times Magazine entitled "What it Means to be a Homosexual." That article, which recalled the abuse and teasing that the author suffered as a child growing up in Iowa, became the basis for a book, "On Being Different."

As an oral historian, Mr. Miller had a way of eliciting previously unknown or obscure details from those he interviewed, then blending facts, anecdotes and quotations in a manner that made the people he was writing about seem earthy and alive.

"He managed to get information out of people they didn't want to give," observed Harry Middleton, director of the LBJ Library in Austin, Tex., shortly after the 1980 publication of Mr. Miller's "Lyndon, an Oral Biography of Lyndon Baines Johnson."

Horace Busby, a longtime Johnson aide and associate, said in a review of the book, "No secret remains. This is Lyndon Johnson true, lunging through life . . . . "

Mr. Miller interviewed dozens of Johnson's friends and associates to write the book, and the picture that emerged was one of what Mr. Miller called an "American Henry VIII," who aimed "barnyard" language more at noses than ears and speared food from the plate of a prime minister's wife at a state dinner.

"I don't think we've ever seen the likes of Lyndon Johnson before, and I doubt that we ever will again," Mr. Miller concluded.

His Truman book, "Plain Speaking, an Oral Biography of Harry S Truman," was published in 1974. It was based on a series of interviews Mr. Miller had had with Truman 12 years earlier, and it was immediately controversial because of Truman's blunt and candid recollections.

Asked why Richard Nixon lost to John F. Kennedy in the 1960 presidential election, Truman told Mr. Miller, "Because Nixon is a shifty-eyed goddamn liar and the people know it." Truman also told Miller that near the end of World War II, Gen. Dwight D. Eisenhower wrote to then Army Chief of Staff George C. Marshall, saying he intended to divorce his wife Mamie.

Mr. Miller, a resident of Brewster, N.Y., was born in Montour, Iowa, and worked at newspapers in Philadelphia before World War II. He was an editor at Yank magazine during the war, then later a contributing editor at Time magazine and an editor at Harper's.

He wrote a novel, "Sure Thing," about loyalty investigations at the State Department in 1949, a time when there was much discussion and controversy about communist infiltration of U.S. government agencies. Later Mr. Miller wrote about the blacklisting of figures in the motion picture industry who had refused to cooperate with congressional investigations of alleged communist influence in Hollywood.

In his article, "What it Means to be a Homosexual," Mr. Miller said that as a child in Iowa he was teased and tormented by his classmates who called him "Sissy, . . . pansy, fairy, nance, fruit, fruitcake . . . . It's not true, that saying about sticks and stones; it's words that break your bones."

But he said the experience made him especially sympathetic to Truman who told stories about being teased as a boy because of his thick glasses and having to take piano lessons.

Mr. Miller leaves no immediate survivors.