Robert K. Walsh, 76, a retired congressional and Supreme Court reporter for The Washington Star and editor of the newsletter of the John Carroll Society of Washington, died of cardiac arrest Monday at Georgetown University Hospital while undergoing cancer surgery.

Mr. Walsh began working for The Star in 1946 and retired in 1969. His Supreme Court coverage included the 1954 ruling ordering racial desegregation of public schools and the celbrated Rosenberg atomic secrets spy case. He was assigned to Capitol Hill about 1954 and remained there until he left The Star.

He was born in McAlester, Okla., and earned a bachelor's degree from St. Louis University in 1924. Mr. Walsh then worked for the old St. Louis Star and St. Louis Globe-Democrat before joining the Providence (R.I.) Journal and Evening Bulletin in 1928. He was a political reporter and editor for the newspaper before coming here as Washington correspondent in 1944.

Following his retirement, Mr. Walsh continued to write on politics and review books for The Star.

He was a member of the National Press Club, where he served on numerous committees, and a member of the standing committee of correspondents at the Capitol, of which he was secretary in the mid-1950s.

Survivors include his wife, Anne G. M., of the home in Washington.