During a meniscectomy, thirty competitive athletes who were less than thirty years old were found to have a non-functional or absent anterior cruciate ligament. Preoperative examination without anesthesia had revealed minimum to mild anterior instability without a positive pivot-shift or jerk test. They all had a meniscectomy without reconstruction of the ligament and all were followed for up to four years (average, 2.6 years). Twenty-five (83 per cent) returned to full athletic activity. All had relief of the symptoms of the meniscal lesion and improved significantly, but six progressed to moderate anterior instability with a positive pivot-shift and jerk test. Nevertheless, four of the six were able to resume unrestricted athletic activity.