Many authors have advocated stapling or epiphysiodesis of the distal medial femur as a means of correcting genu valgum. However, in the literature, aside from clinical improvement (appearance, pain, function), objective evidence of kinetic and kinematic improvement is lacking. Therefore, the authors undertook a prospective gait analysis evaluation of a series of patients treated for genu valgum, comparing pre- and postsurgical measurements to document the benefits of normalizing the mechanical axis. These results indicate that after surgery knee and hip angles and knee moments were returned to within the normal range for a similarly aged control group.