Placido Joseph Scuderi, 56, a representative for Dean Witter Reynolds Inc., a stock and bond brokerage firm here, and an Army veteran of World War II, died Thursday at Holy Cross Hospital in Silver Spring after a heart attack.

A resident of Silver Spring, Mr. Scuderi was born and reared in Washington and graduated from Gonzaga High School.

During World War II, he served as a sergeant in the Medical Corps and in the China-Burma-India theater of operations.

After the war, he returned to this area and graduated from Georgetown University's Foreign Service School.

Mr. Scuderi then worked at the Pentagon for about five years before beginning his career as a stockbroker. He was associated with several local firms before joining the Dean Witter Reynolds firm about five years ago.

He was a member and past president of the Lido Civil Club and the R.E.C. Club, a social organization in Silver Spring. He also was a member of St. John the Baptist Catholic Church in Silver Spring.

Survivors include his wife, Margaret E., and three sons, Joseph, Edward, and Samuel, all of Silver Spring; his mother, Margaret, of Washington; a brother, D. Thomas Scuderi, also of Silver Spring, and a sister, Elvira Torrisi of Andover, Mass.

The family suggests that expressions of sympathy be in the form of contributions to the Hillandale Volunteer Fire Department Medic IV.