Knee meniscectomy is the most common procedure performed by orthopaedic surgeons. While it is generally believed that loss of meniscal tissue leads to osteoarthritis and poor knee function, many variables may significantly influence this outcome. Through literature search engines including PubMed and Ovid, 4 randomized controlled trials, 2 prospective cohorts, and 23 retrospective cohorts that fit the criteria for level I, II, and III level of evidence were included in this systematic review. For the level III evidence studies, follow-up of 5 years or more was required. Preoperative and intraoperative predictors of poor clinical or radiographic outcomes included total meniscectomy or removal of the peripheral meniscal rim, lateral meniscectomy, degenerative meniscal tears, presence of chondral damage, presence of hand osteoarthritis suggestive of genetic predisposition, and increased body mass index. Variables that were not predictive of outcome or were inconclusive or had mixed results included meniscal tear pattern, age, mechanical alignment, sex of patient, activity level, and meniscal tears associated with anterior cruciate ligament (ACL) reconstruction. While an intact meniscus or meniscal repair was generally favorable in the ACL-reconstructed knees, meniscal repair of degenerative meniscal tissue was not favorable. There is a lack of uniformity in the literature on this subject with a preponderance of lower level evidence. Although randomized controlled trials are considered to be the gold standard in medical research, a multicenter prospective cohort design may be more appropriate in assessing the long-term outcome of meniscal surgery and the role that multiple preoperative and intraoperative variables may play in clinical outcomes. In addition, future studies should include factors not assessed or adequately evaluated by several of the included studies, such as meniscal tear pattern, age, mechanical alignment, sex of the patient, activity level, meniscal tears associated with other injuries such as the ACL, smoking, and the effect of previous surgery.