The medium- and long-term results of conservative and surgical treatment of ACL lesions were evaluated by analysis of the current literature. Only reports with a minimum follow-up of 4 years were taken into account. Concerning conservative treatment, the literature search revealed only 7 papers with a total of 636 cases. Reports on the results of surgical treatment were separated into four categories: primary repair, with 13 papers (1205 cases), extraarticular tenodesis, with 4 papers (232 cases), ACL reconstruction, with 26 papers (2693 cases) and ACL prosthetic replacement (reconstruction using synthetics) with 5 papers (370 cases). The mean functional scores show about 70% good and excellent results for all treatment regimens. Clinical laxity persists in almost all conservatively treated cases, in almost half of the cases with primary repair, extra-articular tenodesis, and synthetic substitution, and in almost one-third of the cases with ACL reconstruction. The incidence of secondary ACL surgery was lowest in the conservative group (4.6%), whereas secondary meniscus surgery was lowest in the ACL reconstruction group (3.5%). Compared with the conservative group (12%), surgical treatment evolved to a higher osteoarthritic morbidity. Sports participation was higher in the ACL reconstruction group. This analysis may provide a more realistic view on the outcome of treatment of ACL lesions, and on the relationship between treatment, activity level and osteoarthritis.