Vincent Conrad, 27, an administrative clerk in advertising services at The Washington Post, died Friday while on duty at the newspaper. He had a heart ailment.

%Mr. Conrad had joined The Post in September 1969. At the time of his death, he was in charge of the desk that processes advertisements scheduled to appear in the next day's editions.

"Vince Conrad was one of the hardest working, best liked, most conscientious persons at The Post. He worked closely with all of the paper's advertising sales and production people. Everyon knew him and everyone liked him," Donald E. Graham, publisher, said after learning of his death.

Mr. Conrad was born in Washington and was a graduate of St. Anthonyhs High School.

He was a member of St. Nicholas Catholic Church in Laurel and taught in the Confraternity of Christian Doctrine (Sunday school) at St. Joseph's Catholic Church in Beltsville.

He is survived by his parents, Mr. and Mrs. John N. Conrad, with whom he lived in Beltsville, and by 11 borthers and sisters, Terence M., Shawn D., Lousie C., Kevin P. and Mary I., all of the home, antoinette, Trudy and Patrick F., all of Greenbelt, John T., of Alexandria, Della Dove, of Annapolis, and Bernard, of Louisville, Ky.