We reviewed the long-term results of the treatment of slipped upper femoral epiphysis (SUFE) using realignment procedures in 36 patients (37 hips) at an average follow-up of 33.8 years (26 to 42). There were serious short-term complications in seven of the 22 hips treated by subcapital osteotomy, three of the 11 hips treated by intertrochanteric osteotomy and three of the four hips treated by manipulative reduction. At re-examination, the clinical and radiological results were excellent or good in 41% of the hips treated by subcapital osteotomy, in 36% treated by intertrochanteric osteotomy and in none treated by manipulative reduction. In all, seven hips (19%) had had arthrodesis or total hip replacement. The natural history of SUFE was probably not improved by any of the treatments used in our study. We therefore discourage the use of subcapital and intertrochanteric osteotomy as well as manipulative reduction in the primary treatment of chronic SUFE.