Priscilla Hiss, 81, who maintained the innocence of her husband, Alger Hiss, despite his 1950 conviction for lying to conceal Communist espionage, died Oct. 14 at St. Vincent's Hospital in New York City. She suffered a stroke four years ago and had lived in a nursing home for the past two years.

Alger Hiss, a State Department official who attended the Yalta Conference at the close of World War II, was convicted of lying to the House Committee on Un-American Activities, of which Richard M. Nixon was a member. Nixon was his chief antagonist on the committee and the case was a major turning point in Nixon's climb to national political prominence. Nixon detailed it in his book "Six Crises."

Hiss was named to the committee by former Communist Party member Whittaker Chambers as a member of the party. He was accused of stealing secret State Department documents in the 1930s and transmitting them to Chambers.

Mrs. Hiss maintained her husband's innocence at his two trials for perjury and in battles to clear his name in the years after the court proceedings. She was a witness at both trials and denied prosecution claims that she typed copies of those sensitive documents, given to Chambers in 1937 and early 1938.

Hiss was convicted of perjury in 1950 for telling a grand jury that he was not a spy for the Soviet Union. He spent nearly two years in prison.

Before the limelight of the trials was focused on Mrs. Hiss, she worked as an office manager for Time magazine and taught English at the Potomac School in Washington and the Dalton School in New York. After the trials, she worked at several publishing houses as a book editor.

She was a graduate of Bryn Mawr College and Yale University.

She and Hiss were married in 1929 and separated in 1959. She is survived by her husband and two sons.