Wilhelm made his MLB debut with the Giants on April 18, 1952, at age 29, giving up a hit and two walks while only recording one out. On April 23, 1952, in his third game with the New York Giants, Wilhelm batted for the first time in the majors. Facing rookie Dick Hoover of the Boston Braves, Wilhelm hit a home run over the short right-field fence at the Polo Grounds. Although he went to bat a total of 432 times in his career, he never hit another home run.