Basic science research and follow-up studies after meniscectomy have provided convincing evidence of the importance of preservation of the meniscus in decreasing the risk of late degenerative changes. Whether in a stable or an unstable knee, if a meniscus tear cannot be repaired, a conservative partial meniscectomy should be undertaken to preserve as much meniscal tissue as possible. When feasible, repair should be carried out in young patients with an isolated meniscus tear, despite healing rates that are significantly lower than those obtained when meniscus repair is done with anterior cruciate ligament (ACL) reconstruction. The incidence of successful healing is inversely related to the rim width and tear length. In general, meniscus repair should be limited to patients under 50 years of age. Vertical longitudinal tears, including bucket-handle tears, are most amenable to repair. Some radial split tears can be repaired. In an ACL-deficient knee, meniscus repair is more prone to failure if not performed in conjunction with an ACL reconstruction, and is not recommended. Meniscal allograft surgery is investigational but may hold promise for selected patients.