Cubitus varus, or gunstock deformity, represents the most common complication of supracondylar fracture of the humerus in children, that results from medial tilting of the distal fragment secondary to rotation in the horizontal plane. Actual functional disability is rare, however, operative treatment is frequently indicated for cosmetic reasons in the growing period. Several types of osteotomies have been advocated to correct the deformity. When corrective osteotomy is done in adolescence or adult, the final results are not always satisfactory. We analyzed roentgenograms of 26 patients from the viewpoint that when the treatment of cubitus varus deformity is neglected or delayed, the residual cosmetic deformity may become worse because of enalrging lateral humeral condyle and radial head with growth. The results are summarized as follows; 1. Degree of cubitus varus deformity was the most severe in the group who were injured under the age of 5 years old. 2. Radiological increase of height and width of the radial head were found in all cases. The most severe changes were found in those who were injured at the age of between 6 and 10 years. 3. In adult patients with higher degree of cubitus varus, there were incongruity between the capitellum and the radial head, and the articular surface of radial head was flat rather than concave. Based on these findings, we conclude that correction of the cubitus varus deformity should not be unduely delayed in order to minimize the secondary changes of radial head and lateral condyle of the humerus, and to obtain satisfactory cosmetic outcomes.