Premature closure of the capital femoral physis after pin fixation of slipped capital femoral epiphysis (SCFE) in the juvenile population (at least 1 year less than the established mean) can lead to growth disturbances of the proximal femur. A retrospective review of 21 patients (33 hips) who had a pinning of a juvenile SCFE was performed. Growth disturbances including greater trochanteric overgrowth, coxa vara, and coxa breva were noted in 64% of the hips. An 80% incidence of bilateral involvement was noted in the juvenile group. Consideration should be given to prophylactic pinning of the contralateral hip and use of a smooth pin construct to prevent premature closure of the growth plate in children with significant growth remaining.