Discoid meniscus is a congenital variant of the knee joint that typically involves abnormal morphology and potential instability of the lateral meniscus. Some discoid menisci have abnormal peripheral attachments and are unstable. Discoid menisci are prone to tearing secondary to increased thickness, poor tissue quality, and instability. Patients may or may not be symptomatic. Torn or unstable discoid menisci cause mechanical symptoms, pain, and swelling. Symptomatic patients in whom nonsurgical management fails most frequently are treated with arthroscopic surgery. Historically, complete meniscectomy has successfully alleviated symptoms but has resulted in poor midterm results, with degenerative changes to the knee joint. Current treatment emphasizes the saucerization of the meniscus, with removal of the central disk and retention of the peripheral crescent. Peripheral meniscal repair is performed when instability is present. Short-term results are good; however, degenerative changes have been reported at intermediate follow-up.