During a 15-year Major League Baseball (MLB) career, he played for the San Francisco Giants (1963–68), the Houston Astros (1969–73; 1978–79), the Oakland Athletics (1973–74), and the New York Mets (1975).

[3] In 1964, his first full year in the major leagues, Alou batted .274 with little power, but on July 10, he went 6-for-6 with five singles and a home run.

Alou was selected by the Montreal Expos in the 1968 MLB expansion draft and then was traded to the Houston Astros with Donn Clendenon for Rusty Staub.

Alou was released by the Athletics towards the end of March 1975, before the start of the 1975 season,[8] and he signed with the New York Mets on April 10.

[6] Alou later served as a scout for the Expos, then moved to the Florida Marlins as the club's director of Dominican operations.