Purpose. To report outcome of Scarf osteotomy with or without proximal phalangeal osteotomy for correction of severe hallux valgus deformity. Methods. Records of 48 women and 4 men aged 28 to 68 (mean, 52) years who underwent 57 Scarf osteotomies with or without proximal phalangeal osteotomy for severe hallux valgus by a single surgeon were reviewed. The patients had a hallux valgus angle (HVA) of up to 55 degrees. An additional proximal phalangeal osteotomy was performed in 11 of the patients whose hallux valgus persisted (HVA > 10 degrees). The American Orthopaedic Foot and Ankle Society (AOFAS) hallux score, the HVA and intermetatarsal angle (IMA) on radiographs, and the complication rate were assessed. Results. The mean follow-up period was 26 (range, 24-36) months. The mean AOFAS hallux score improved from 57.4 (range, 49-64) to 91.6 (range, 75-100). The mean HVA improved from 38.1 degrees (range, 28 degrees-52 degrees) to 12.8 degrees (range, 5 degrees-20 degrees). The mean IMA improved from 17.0 degrees (range, 13 degrees - 24 degrees) to 6.8 degrees (range, 3 degrees-10 degrees). One patient developed chronic regional pain syndrome. There were no instances of non-union, delayed union, or malunion of the osteotomy site. Conclusion. Scarf osteotomy with or without proximal phalangeal osteotomy is an effective treatment for correcting severe hallux valgus deformity.