Plica is a general term for folds in the synovial membrane of the knee. Sometimes plica can progress to a pathologic level and clinically important condition. Normally, plica has an elastic structure and slides softly between femur condyles when flexing or extending the knee. If it is inflamed and thickened due to edema, it loses its elasticity and becomes symptomatic. Plica syndrome is a cause of frontal knee pain. Pain is generally located in the anterior knee, but can be seen in the anteromedial, anterolateral, medial, and lateral joint spaces. In physical examination, during knee extension, sensitivity is present 1-2 cm proximal and medial to the lower pole of the patella. It is a typical sign. Magnetic Resonance Image is the best non-invasive diagnostic tool for plica syndrome. In all cases, conservative treatment should be the first choice. Surgical treatment is used for patients who do not respond to conservative treatment. Surgical excision of mediopatellar plica associated with cartilage degeneration appears to result in substantial clinical improvement, thus representing an effective treatment modality for this group of patients.