Mike McGrady, an award-winning journalist who wrote on subjects from war to domestic life but was best known for a literary spoof, “Naked Came the Stranger,” that became a surprise bestseller in 1969, died May 13 at a hospital in Shelton, Wash. He was 78.

He had pneumonia, his brother, Seamus McGrady, said.

Mr. McGrady was a columnist for Newsday, a newspaper on New York’s Long Island, when he became the ringleader of one the country’s most successful literary pranks. After interviewing the authors of several best-selling bodice-rippers, he thought that he and other journalists could do just as well.

“I was really fed up with people like Harold Robbins and Jacqueline Susann,” he told the Associated Press in 1969. “I saw the writing that was being accepted and it seemed absurd.”

Three years earlier, Mr. McGrady issued a memorandum in which he invited other Newsday journalists to join him in writing a heavy-breathing parody set mostly in the bedrooms of Long Island. He came up with the title and gave 25 writers a deadline of one week in which to churn out one chapter each.

“There will be an unremitting emphasis on sex,” Mr. McGrady wrote in his memo. “Also, true excellence in writing will be quickly blue-penciled into oblivion.”

The project stalled because Mr. McGrady went to Vietnam to cover the war. (His newspaper series about the war, “A Dove in Vietnam,” was published as a book in 1968 and won the Overseas Press Club award for foreign reporting.)

Mr. McGrady then spent a year at Harvard on a Nieman fellowship before returning to Newsday and picking up the loose ends of “Naked Came the Stranger.”

“Everyone handed in a chapter, and most were bad enough to merit consideration,” Mr. McGrady later recalled. “Some of the chapters were too good and had to be sent back for revisions.”

He and another columnist, Harvey Aronson, stitched the pastiche together into something resembling a novel. Mr. McGrady’s sister-in-law posed as the author, “demure Long Island housewife” Penelope Ashe — a name dreamed up by Mr. McGrady. The manuscript was published by Lyle Stuart, who had a penchant for printing attention-getting books.

The plot of “Naked Came the Stranger,” such as it was, concerned a Long Island housewife, Gillian Blake, who was the host of a radio talk show with her husband. Suspecting her husband of having an affair, Gillian takes revenge by seducing other men and destroying their marriages.

Each chapter depicts her dalliances with lawyers, executives, a pornography king, a suburban gangster, a rabbi, a prizefighter and a man who had previously been exclusively homosexual.

The writing was riotously over the top.

“Faster and faster they communicated,” went one passage. “Fingers on skin, teeth on skin, then great shudders of total communication, and explosions of understanding. Afterward, Morton said, ‘I’d forgotten there was more to life than mowing a lawn.’ ”

According to a 1969 story in Life magazine, by the end of the book, the suburban toll included “one abortion, five divorces, three separations, one mental breakdown, two suicides and one murder.”

Mr. McGrady’s collaborators, who received about $5,000 each for their efforts, included two Pulitzer Prize-winners, Gene Goltz and Robert W. Greene; William McIlwain Jr., who became a top editor of the Washington Star; George Vecsey, who spent many years as a sports columnist at the New York Times; and Marilyn Berger, who later wrote for The Washington Post and the Times.

Soon after “Stranger” was published in August 1969, the hoax was exposed, but the book was a sensation, selling 100,000 copies in hardback and reaching No. 4 on the Times bestseller list. A paperback edition sold in the millions.

Mr. McGrady turned down a $500,000 offer to produce a sequel but, in 1970, did publish a related book, “Stranger Than Naked, or How to Write Dirty Books for Fun & Profit.”

Michael Robinson McGrady was born on Oct. 4, 1933, in New York City and grew up mostly on Long Island. After graduating from Yale University in 1955, he served in the Army before joining Newsday, where he wrote about civil rights and served as the paper’s movie reviewer and restaurant critic.

Mr. McGrady once spent a year at home while his wife worked. He wrote about that experience in his 1975 book, “The Kitchen Sink Papers: My Life as a Househusband.”

He published several novels and, in the 1980s, wrote two books with Linda Lovelace, in which she said she was coerced into acting in “Deep Throat” and other pornographic movies.

After retiring from Newsday in 1991, Mr. McGrady moved to Lilliwaup, Wash. Survivors include his wife of 53 years, Corinne Young McGrady of Lilliwaup; three children, Sean McGrady of Los Angeles, Liam McGrady of Delray Beach, Fla., and Siobhan Benoit of Boynton Beach, Fla.; a brother; and five grandchildren.

“Naked Came the Stranger” was reissued in 2004 and is still in print. Mr. McGrady and the other writers had nothing to do with a hardcore 1975 film with the same title. They did, however, see the movie at a Times Square theater.

During one vivid scene, Aronson told the Charlotte Observer, someone shouted, “Author, Author!”

“Seventeen of us stood up.”