Purpose: Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement. Methods: To correct deformity and diminishim pingement, we performed epiphysiodesis combined with an Imhauser intertrochanteric osteotomy (ITO) in moderate and severe slipped capital femoral epiphysis. We downgraded the angle of the head relative to the acetabulum into an angle corresponding to a mild slip or even an anatomical position. Our hypothesis is that the avoidance of anterior impingement at an early stage can prevent the development of osteoarthritis. Results: The results of 28 patients (32 hips) were evaluated. Outcome parameters were SF-36, Harris Hip Score, range of motion, Kellgren-Lawrence score, chondrolysis and avascular necrosis. After a median follow-up of 8 (range 2-25) years, the group was clinically, functionally and socially performing well. Radiologically, there was no sign of chondrolysis or avascular necrosis, and more than 80% of the patients did not show any signs of osteoarthritis. Conclusions: Based on these results, we conclude that a one-stage Imhauser ITO combined with epiphysiodesis performed on patients with moderate and severe SFCE gives satisfactory results.