Arthroscopy is now well established as a method of diagnosing meniscal lesions, and its advantages have been pointed out in several reports. Arthroscopic surgery, however, is difficult to master, so that for meniscectomy open methods remain commoner. By taking advantage of the new instruments and equipment developed for arthroscopic operations, a modified technique of open meniscectomy, designed to improve the postoperative course, has been developed. In a prospective randomised study, the results after this modified open meniscectomy were comparable with those obtained after arthroscopic operation and were significantly better than those after conventional meniscectomy. The best results of all, however, were those after partial arthroscopic meniscectomy.