Wiley T. Buchanan Jr., 73, a former ambassador to both Austria and Luxembourg who was the U.S. chief of protocol from 1957 to 1961, died Feb. 16 at the Potomac Valley Nursing Home. He had Alzheimer's disease.

Mr. Buchanan, who lived in Washington, was a native of Texas. He attended both Southern Methodist University and George Washington University. He began his government career during World War II with the War Production Board. From 1950 to 1952, he was an official of the old National Production Authority.

Appointed minister to Luxembourg in 1953, he was promoted to ambassador two years later. He held that post until becoming protocol chief. He served as ambassador to Austria from 1975 to 1977. He was the author of the 1964 book, "Red Carpet at the White House," which told of his days as protocol chief.

Mr. Buchanan had pursued a variety of private investments over the years. He was a former member of the board of directors and executive committee of the L'Enfant Plaza Corp. He was a member of the Federal City Council and the board of the National Symphony. He had been a trustee of several organizations, including George Washington University and Johns Hopkins University's School of Advanced International Studies. He was a member of the Metropolitan and Chevy Chase clubs.

Survivors include his wife, Ruth, and a son, Wiley T. III, both of Washington; two daughters, Bonnie Matheson of The Plains, Va., and Diane Wilsey of San Francisco; a brother, Avon, of Dallas; a sister, Aba Inglish of San Antonio, and seven grandchildren.