Results of surgical treatment for chronic Monteggia's lesions in 16 children were retrospectively analyzed. The mean age at the time of reconstructive surgery was 7 years and 8 months. Using Bado's classification, there were 12 type I, 3 type III lesions, and 1 type IV lesion. In 11 cases, operative procedures consisted of a combination of corrective ulnar osteotomy and open reduction of radial head. Corrective ulnar osteotomy alone was required in 2 cases. Another two cases required a combination of corrective osteotomy of both radial and ulnar shafts. Annular ligament reconstruction had to be performed in only 1 case initially submitted to open reduction of radial head. The patients were examined at 9 years and 6 months of the initial reconstructive procedure on an average. Using the scale proposed by Morrey, there were 9 good, 4 satisfactory, and 3 poor results. Eleven complications were recorded including 2 radial nerve lesions, 2 nonunions at the site of ulnar osteotomy, 5 redislocations and 1 subluxation, and 1 ulnar fracture below the site of osteotomy. Seven of 11 patients with complications underwent repeat operative procedures. These seven patients included both children previously submitted to combined osteotomies of both the ulna and radius as well as both children who had undergone corrective ulnar osteotomy alone. Thus, a very high rate of complications was recorded in our series of patients undergoing operative treatment for the sequels of Monteggia's lesions. In our opinion, the main reason for this was inappropriate choice of operative treatment. Reporting on this very high rate of complications may hopefully draw attention to the fact that reconstructive procedures to correct the sequels of Monteggia's lesions should not be attempted before learning the basic principles that need to be addressed. These are reconstructive procedures that should only be performed after a thorough study of the possible complications. Based upon this survey of our experience, we conclude that in addition to ulnar deformity correction, open reduction and stabilization of radial head are mandatory to achieve a satisfactory result.