As a manager for the Cubs, he led the team to National League championships in 1932, 1935 and 1945. He also served as the Cubs' Director of Player Personnel, then the club's title for general manager, from his resignation as field manager in mid-1949 through early 1950. However, Grimm was not comfortable in his front-office post and resigned in February 1950 to manage a Double A team, the Dallas Eagles of the Texas League.