Sixteen patients with 20 forearm deformities were reviewed. The deformities were classified into three types. The degree of ulnar tilt of the radius, ulnar displacement of the carpus, and relative ulnar shortening were determined. The severity of the deformity correlated with these measurements. Metacarpal lengths were also measured. Significant metacarpal shortening without exostoses was seen in 10 of 11 patients and with exostoses remote from the metaphysis in 10 of 13 patients. Metacarpal shortening correlated with the type and severity of deformity.