After four seasons as a backup in St. Louis, Tolan got his chance as an everyday outfielder when he and Wayne Granger were traded to Cincinnati for Vada Pinson on October 11, 1968. Using a distinctive batting style, with his bat held high above his head and perpendicular to the ground, Tolan had brilliant seasons in 1969 and 1970. Batting second behind Pete Rose, he had career highs of 21 HR and 93 RBI in 1969. He batted .316 and led the NL with 57 stolen bases in 1970. In Game Two of the 1970 LCS, he homered and scored all three Cincinnati runs in their 3-1 victory over Pittsburgh.
Tolan ruptured his Achilles tendon playing basketball in January 1971 and missed the entire season. He came back in 1972 to bat .283 and steal 42 bases, capturing TSN Comeback Player of the Year honors. But he feuded with Cincinnati management, was suspended during a dismal 1973 season, and was traded to San Diego in November. A 1974 knee injury eliminated his speed, and he played sparingly after joining the Phillies in 1976, mostly at first base. He spent 1978 in Japan. Later he served as a major league coach and a minor league manager.