One pattern of injury to the triangular fibrocartilage complex (TFCC) is a traumatic peripheral tear located at the ulnar end of the TFCC. Since 1989, this specific injury has been classified as a Palmer type 1B lesion. Various treatment options have been described for 1B injuries, yet when there is coexistent ulnar positive variance, it can make the choice of treatment difficult. The purpose of this article is to help the surgeon decide how to treat type 1B lesions in ulnar positive patients by directly comparing arthroscopic repair (repair) to ulnar shortening osteotomy (USO). The null hypothesis was that repair and USO would provide equivalent postoperative improvement with regard to motion; Disability of the Arm, Shoulder, and Hand (DASH) score; visual analog scale (VAS) score; and grip strength. We tested our hypothesis by retrospectively reviewing prospectively collected data from 51 patients treated surgically between 2000 and 2006 with type 1B tears in the setting of ulnar positive variance. Of these 51 patients, 27 were treated with arthroscopic repair and 24 with USO. All patients were evaluated before surgery as well as at final follow-up for active range of motion measurements, grip strength, DASH score, and VAS score. Radiographs were taken of all patients before surgery to confirm the presence of ulnar positive variance, and after surgery in the USO group to evaluate for bony union. At the final follow-up, we found no statistically significant difference between the repair and USO groups with regard to flexion, extension, pronation, supination, radial deviation, or ulnar deviation. Likewise, there was no significant difference in grip strength, DASH scores, or VAS scores. When analyzing each cohort individually, both groups improved significantly after surgery with regard to DASH score, VAS score, and wrist extension. There was also a trend toward improved motion in all other directions except for an insignificant decrease in postoperative pronation in the repair group. Two patients in the USO group required additional surgery, with one revision performed for nonunion and one for painful hardware, which caused extensor carpi ulnaris tendonitis. The results of our study suggest that type 1B TFCC tears in the ulnar positive patient can be managed equivalently well with repair or USO. Therapeutic III.