Objective: To assess the outcomes of patients with ulnar impaction syndrome, undergoing ulnar shortening osteotomy. Material and Methods: Descriptive, longitudinal, and ambispective study. In all, 26 patients were assessed, in which an ulnar shortening osteotomy was performed during 4 years, with Mayo and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scales, force measurement, range of motion, and pain. Patients who underwent shortening osteotomy because of ulnar impaction syndrome were included. Frequency and descriptive statistics and Wilcoxon rank sum test for a single sample was performed. It was considered as statistically significant, a value P < .05. Introduction: The ulnar impaction syndrome is a positive ulnar variance, which causes an impingement of the triangular fibrocartilage complex between the ulnar head and lunate in one side and the pyramid on the other side. It is characterized by a pressure increase in a longitudinal direction. Ulnar shortening osteotomy is an alternative management that seeks decompression of the triangular fibrocartilage complex, by an extra-articular ulnar shortening at its distal third, to decrease pain and increase the range of motion. Results: Mean age of patients was 39 years. The predominant sex was male in 67%. In 65% of the cases, the affected hand was the right. The follow-up of the patients was in average 41 months, the patient with a longer observation time was 63 months and the shortest time 13 months. The improvement in pain was evident, from an average of 8 preoperative to 1 postoperative, with mild in most patients with disabling residual pain in only 1 case. Improvement was observed in the range of motion in all patients, with improvement in flexion, extension, radial, and ulnar deviation ( P < .05). The Mayo scale reported on average a score of 82. The QuickDASH scale postoperative indicated an average score of 16. With these results, we found that 85% of patients studied had no disabilities, 11% had mild disability, 4% moderate disability, and none presented severe disabilities. The complications were 1 case of nonunion (3.8%), complex regional pain syndrome (3.8%), and did not show any case of infection. In 7 cases (27%), removal of osteosynthesis material was required by pain and swelling at the surgical site. Conclusions: Ulnar shortening osteotomy tight the remaining ligaments and the interosseous membrane, setting the articular surface in a biomechanical advantage. It is an extra-articular simple technique, with a low cost and does not require special implants, which has a tendency to decrease pain and improve functional disability of the limb.