Helmut Benthaus started his professional career at Westfalia Herne in 1958. In 1959 he won the Oberliga West title but left just a year later to join 1860 Munich before moving to 1. FC Köln. He won the Oberliga West again in 1963 with Köln, then the German Bundesliga in 1964. In 1965 he joined Swiss club FC Basel as player-manager. He retired from playing in 1971 aged 36.
Benthaus coached FC Basel for 17 years between 1965 and 1982. He won the Swiss Championship seven times and the Swiss Cup twice. He coached Basel's legendary team of the 1970s that won the Championship in 1970, 1972, 1973 and 1977 as well as the Cup in 1975. The squad included Karl Odermatt and Ottmar Hitzfeld. After Basel he joined German club VfB Stuttgart in 1982. There he won the Bundesliga in 1984. He left in 1985 and rejoined Basel. However, this spell was much less successful and he retired in 1987.