After four years on the Physical Education Staff, Peppe became the first swimming and diving coach at Ohio State in January of 1931. Assisting him on his staff was Coach L. W. St. John. In his earliest years as coach, Peppe's teams were only runners-up on the national level in 1937, 1938, and 1939. But, after winning their first national championship in 1943, Ohio State had unheralded success. In the twenty years from 1943 to 1963, there were only six years when Peppe's Ohio State teams failed to finish first or second in the national swimming and diving competition. Under Peppe, Ohio State had NCAA or national Championships in 1943, 1945, 1946, 1947, 1949, 1950, 1952, 1954, 1955, 1956, and 1962. His teams were undefeated in dual meets during 12 seasons. Peppe is considered to have laid the foundation for the tremendous legacy of excellence associated with Ohio State's swimming and diving teams. His swimmers and divers dominated the sport in a way few teams have ever matched. Under his studied management, Ohio State Swimmers won 312 individual championships, which included 94 NCAA, 100 AAU and 94 Big Ten titles. During his tenure at Ohio State, his swimmers won 5 Olympic gold medals and 19 of his athletes qualified for the U.S. Olympic team. In both 1947 and 1956, excelling even more as a diving coach, Peppe's divers took 1st through 4th place, dominating the competition in the NCAA diving finals. By 1953, his teams had won six indoor and four outdoor American Athletic Union national titles, before college teams were excluded from the competition.
Bob Bartels, both Peppe's Assistant Coach and 1951-53 Ohio State swimmer under Peppe, replaced him as Head Coach in 1963. Peppe's coaching strategy was to analyze each swimmer and develop a training program that addressed individual shortcomings, with the goal of producing the best performance in competition. He contributed a wide variety and a large number of articles on swimming to newspapers and magazines. ==International coaching==