Twenty-eight patients were treated by ulnar shortening osteotomy for static or dynamic ulnar impaction syndrome. Ulnar variance was measured on a true anteroposterior radiograph. There were 25 wrists that were too long, two neutral, and one that was short. Bones were shortened by a mean of 3.5 mm. Mean follow-up time was 29 months (range 7–60), all with confirmed consolidation. At final follow-up mean grip strength had improved from 67% to 75%, mean Disabilities of the Arm, Shoulder, and Hand (DASH) score from 40 (range 12–83) to 26 (range 0–61) and mean range of movement from 80% (range 40%–100%) to 88% (range 50%–100%). Smoking, age at operation, type of osteotomy (transverse or oblique), dominance of hand, and sex did not influence consolidation or functionality. Special attention was paid to the anatomy of the distal radioulnar joint and the inclination of the sigmoid notch of the radius. There was no correlation between the anatomy and the functional outcome scores. Mean consolidation time (10 months) (range 2–32) and return to work were longer than in similar studies. Our findings confirm the usefulness of ulnar shortening osteotomy in the relief of ulnocarpal impingement symptoms.