A 38-year-old male patient was admitted to our clinic with the complaints of pain and swelling in his right knee for two years. He had mechanical symptoms for nearly six months. Merchant and lateral knee X-ray revealed calcification in the medial patellar retinaculum. Magnetic resonance imaging demonstrated increased ossification and cortical irregularity in the patella's medial and inferior pole. Due to long-term complaints of the patient, arthroscopy was planned with the preliminary diagnoses of patellofemoral chondromalacia, cartilage degeneration and mediopatellar plica (MPP) syndrome. Arthroscopy revealed a calcific MPP, an interesting entity. It should be kept in mind that plica may become calcific in patients with suspected MPP and the complaints of the patient may not disappear within if left untreated.