A retrospective review of 264 patients treated for slipped capital femoral epiphysis (SCFE) identified 36 who developed avascular necrosis (AVN). Twenty-two patients (24 hips) were evaluated at an average follow-up of 31 years. Nine have undergone reconstructive surgery: four during adolescence and five during adulthood. The remaining 13 patients (15 hips) have had no further operations, but all show degenerative changes on current roentgenograms. The natural history appears to be that of gradual degenerative changes for which reconstructive surgery most often can be delayed until adulthood.