Knee pain is a very common complaint seen in the clinical setting. A torn medial meniscus, osteochondral defects, inflammation, or an irritated medial plica are some of the most common causes of medial knee pain. Plicae are synovial invaginations that are believed to be remnants of the embryological development of the knee. They have a potential to become inflamed and symptomatic. Diagnosis of medial plica syndrome involves physical exam and imaging studies, but the current gold standard is arthroscopy and therefore a definitive diagnosis cannot be made until surgery. As such, medial plicae are the most commonly missed diagnoses in the knee as it is purely a clinical diagnosis. Medial plica syndrome can be treated with physiotherapy, corticosteroid injections, or surgery. Overall, good outcomes have been seen following diagnosis and treatment of medial plica syndrome, with patients returning to their preferred levels of activity. This article reviews the topic of medial plica syndrome.