Purpose: The goal of this study was to compare the results of open scaphocapitate, fusion and revascularization with the results of arthroscopic scaphocapitate fusion and capitate pole excision. Type of Study: Prospective randomized study. Methods: Between April 1997 and January 2000, 16 consecutive patients (5 men and 11 women with a mean age of 31 years [range, 18 to 61]) presenting with Kienbock's disease stage IIIA and stage IIIB were randomized to either open scaphocapitate fusion and lunate revascularization (group I) or fully arthroscopic scaphocapitate fusion and capitate pole excision (group II) groups. Cannulated 3.5-mm ASIF screws were used for the purpose of scaphocapitate fixation in both groups. Operation time, hospital stay, time to fusion, range of wrist motion at final follow-up, grip strength, and return to unrestricted activities of daily living were evaluated at 33 months' follow-up. Results: The mean operating time (153 v 99 minutes), hospital stay (3.6 v 2.3 days), and return to unrestricted daily activities (15 v 5.8 weeks) were shorter in group II. Average time to radiographically evident fusion was shorter in group I (7.25 weeks v 9 weeks). There was a significant increase in grip strength and in range of motion at final follow-up in both groups, and the final grip strength and range of motion was not different between the groups. There were no major complications in either group. Conclusions: Although the number of patients was small and the follow-up period was short, arthroscopic scaphocapitate fusion and capitate pole excision in stage IIIA and IIIB Kienbock's disease resulted in shorter operating time, shorter hospital stay, earlier return to unrestricted daily activities, and equal range of motion and grip strength as compared with open scaphocapitate fusion and lunate revascularization. Determination of specific surgical indications for the benefits of arthroscopic treatment of Kienbock's disease must be analyzed in larger studies.