Our experience with the surgical treatment of radio-ulnar synostosis in the period from 1985 to 1992 is reviewed. Operative procedures were performed in eight patients with radio-ulnar synostosis. In five patients bilateral, and in three patients unilateral, synostosis was present. The results were better in patients in whom synostosis mass osteotomy perpendicular to the longitudinal axis of the forearm was performed. Usually, treatment attempts to achieve a neutral position for the forearm. This position is more suited to unilateral synostosis than to bilateral synostosis. Vascular and/or neurological complications did not arise during the operation or during the follow-up period. All patients were satisfied with the operative outcome.