Synovial plicae around the knee are a relatively common occurrence but one that is rarely responsible for symptoms. The Plica syndrome has been well described but controversy still exists regarding its diagnosis and treatment. We have reviewed and studied the published literature both past and present in detail regarding synovial plicae around the knee to provide a comprehensive and up-to-date review on the subject. The aim is to outline previous significant research into the embryology and pathology of synovial plicae as well as providing a review of the current thinking on treatment options available for the different synovial plicae with reference to the evidence available.