Forty-nine patients (52 knees) with untreated anterior cruciate ligament (ACL) ruptures were evaluated an average of 14 years after injury. The results were compared with those of a ten-year follow-up study on the same patients. Eighty-six percent of the knees had one or both menisci removed. There had been little change in symptoms, except that the incidence of giving way had decreased. The incidence of anterior laxity and rotary instability continued to be high. Seventy-five percent of the patients continued to participate in strenuous sports. The incidence of degenerative changes on roentgenograms had increased, with one-third of the knees demonstrating joint space narrowing or unequivocal evidence of osteoarthritis. Development of degenerative changes was associated with varus deformity, meniscectomy, and relatively heavy body weight.