BACKGROUND Aim of this retrospective study was to analyse the long term results after basal closing wedge osteotomy for correction of metatarsus primus varus and hallux valgus in the younger patient. METHODS 49 patients (70 feet) were operated according to a basal closing wedge osteotomy from 1974 to 1985 at our institution. Age was under 40 years in all patients at the time of surgery. 34 patients (50 feet) were evaluated in respect to their clinical and 26 patients (37 feet) to their radiological outcome. The average age was 26 years (14-39 years). The follow-up was 12 to 22 years (Median: 18 years). Analysis was performed using the patient's record, weight-bearing X-rays, a standardized questionnaire and clinical investigation. RESULTS 82% of the patients had very good and good subjective results. Cosmetics was rated very good and good in 78%, 88% of the patients were painfree. Radiological analysis at follow-up: Hallux valgus-angle 19,3 degrees, intermetatarsal I/II-angle 6 degrees, shortening of first metatarsale 5 mm, at average; dorsal elevation of first metatarsale 38%, degenerative arthritis of the metatarsocuneiforme joint 19%, congruency of first metatarsophalangeal joint 54%,sesamoid subluxation: 46% grade 0, 30% grade I, 14% grade II and 10% grade III. In 14 feet (28%) metatarsalgia was found. CONCLUSIONS The basal closing wedge osteotomy is rather a technically demanding procedure conjuncted with a higher risk of failure. Satisfactory long term results can be obtained by an ideal operating technique. As undesirable side effects shortening of the first ray and dorsal malangulation of the first metatarsale may occur consecutively leading to metatarsalgia. Lower risk procedures like the crescentic osteotomy according to Mann or chevron osteotomy should be preferred.