Lorenzo Bosisio’s real interest in cycling started after joining the V.C. Melzo club. His best year was 1968, when he won a team pursuit World Championship, and added bronze in individual pursuit at the Worlds and the Mexico City Olympics. He also won bronze in the road team time trial at the 1967 Worlds.
Bosisio turned pro in 1968 and competed on the road, but with little success. On the track, however, he won silver in individual pursuit at the 1970 World Championships. He also added silver medals in individual pursuit at the Italian track nationals in 1969, 1970, and 1971. Bosisio was awarded the Gold Medal of the Italian Olympic Committee for his achievements.