Aims: The aim of this prospective study was to analyse the Ludloff osteotomy for its potential of correcting hallux valgus deformity. Methods: Between September 1998 and October 1999 84 consecutive patients who underwent a Ludloff osteotomy were included in this prospective study. All patients were examined preoper-atively and at a minimum follow up of 2 years according a standardized questionnaire based on the HMIS of the American Foot and Ankle Society. X-rays were taken preoperatively, at 6 weeks and at þnal follow up. Results: 75 patients were available for an average follow up of 33 months (24 to 41). The average preoperative HMIS was 52 points and at follow up 87 points. 78% of the patients rated the outcome as excellent and good. 82% of patients were painfree at follow up. Radiological evaluation revealed a preoperative average hallux valgus angle (HV) of 36û and a preoperative average intermetatarsal angle (IM) of 17û This was corrected by surgery to an average HV of 14û and an average IM of 8û. Preoperatively sesamoidposition Grade III was present I 71%, Garde II in 29%. At follow up Grade 0 was present in 60%m Grade 1 in 37% and Grade2 in 3%. There was no Grade 3 sesamoid position at follow up. Conclusions: The ludloff osteotomy is a good alternative for the correction of severe hallux valgus deformity. In elderly patients and osteoporotic bone early weight-bearing should not be allowed because of poor bone quality.