This article reviewed the major sports medicine conditions affecting the knee and their MR imaging appearance. MR imaging of the knee is considered efficacious especially in the setting of indeterminate clinical findings and can stratify patients, guiding further surgical management. MR imaging affects the diagnosis and management of acute knee injury by improving clinician diagnostic certainty, assisting in management decisions, and decreasing the number of arthroscopic procedures. From a societal perspective, knee MR imaging can be considered a cost-effective modality when compared with diagnostic and borderline therapeutic arthroscopies (e.g., debridement alone). For these and other reasons, knee MR imaging has shown a substantially increased use for the evaluation of sports medicine conditions.