The purpose of this study is to evaluate arthroscopic ulnar shortening with the holmium:yttrium-aluminum-garnet (Ho:YAG) laser for the treatment of ulnocarpal abutment syndrome (UAS). This is a retrospective review of the experience of a single surgeon using this technique between 1994 and 2000. Unloading the ulnocarpal joint is the recognized treatment of UAS. Ulnar shortening via a diaphyseal osteotomy and plating (USO) has been used with good results; however, nearly 50% of patients will require hardware removal. Researchers have reported similar results between open distal ulnar resection (the wafer procedure) and USO for the treatment of UAS. Researchers have also reported similar results with mechanical arthroscopic distal ulnar resections (arthroscopic wafer distal ulnar resection [AWP]) for UAS. Eleven patients who underwent Ho:YAG laser-assisted arthroscopic distal ulnar resection were retrospectively evaluated. The average follow-up time was 31 months, with a range of 7 to 61 months. Evaluation using Darrow’s criteria revealed 64% excellent (7 of 11), 18% good (2 of 11), 9% fair (1 of 11), and 9% poor (1 of 11) results. The average return to work time was 4.7 months, with a range of 1.5 to 16 months. Complications included 1 repeat surgery for ulnocarpal scar formation, 2 cases of transient tendonitis, and 1 portal site erythema without drainage that was treated with antibiotics. One patient (the one with a poor result) has not returned to work for unrelated reasons. χ- square analysis (P < .05) was unable to identify a statistical difference between the reported results of arthroscopic wafer procedures, USOs, and open wafer procedures. We concluded that Ho:YAG laser-assisted arthroscopic ulna shortening procedures show similar results to those reported for arthroscopic wafer procedures, open wafer procedures, and USOs. Return to work times are similar to those reported by other researchers, as is the return to preoperative occupation rate. There is no need for late removal of hardware, as is sometimes associated with USO. Our experience has been that the Ho:YAG laser removes hyaline cartilage and subchondral bone rapidly and with little debris, and thus facilitates the ulna shortening procedure.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 9 (November- December), 2002: pp 1046–1051