We retrospectively reviewed the record of 89 patients with complete anterior cruciate ligament injury, documented by arthroscopic examination to investigate the long-term results in relation to the generation of osteoarthritis. The mean age of the patients was 34.9 years at follow-up and the mean duration of follow-up was 12.0 years. The mean Lysholm score was 89 points at follow-up. The mean Tegner activity score was 5.7 points before injury and 4.5 points at follow-up. Plain radiographs revealed 63% of osteoarthritis and 37% of which had joint space narrowing. The age of the patients, the level of sports activity, the history of meniscectomy, obesity and the osteoarthritis of the contralateral knee were found to be significant risk factors in osteoarthritis after anterior cruciate ligament injury. The most influential factor for osteoarthritis was considered meniscectomy, in combination with the risk factors of primary osteoarthritis. It should also be noted that modification of sports activity level was the most important factor for avoiding the combined injury of meniscus and osteoarthritis.