P atell cubiti is a patella-like sesamoid bone in the triceps brachii tendon. 1 Its etiology is unknown and theories include congenital, developmental or traumatic injury. Normal radiography shows an ossicle projected posterior to the elbow joint. This case study aims to increase the awareness about the existence of patella cubiti. Case reportA 39 year-old-man with acute left elbow pain after a motor vehicle accident was admitted. At presentation, he was found to have swelling and tenderness at the distal third of the caudal aspect of the left elbow. Examination revealed tenderness with a palpable gap at the triceps brachii tendon insertion, proximal to the olecranon. The triceps brachii tendon of the left elbow joint had full function and full range of motion. AbstractPatella cubiti is a rare anomaly of the elbow, which can be unilateral or bilateral. It is a sesamoid bone in the triceps brachii tendon. The patella cubiti can be asymptomatic or symptomatic, with limitation of motion, stiffness or pain. Radiography shows a smooth well-corticated ossicle projected posterior to the elbow joint. This can be mistaken for a post-traumatic non-union of an old fracture of the olecranon tip. Radiology data and clinical examination are both important and key to an accurate diagnosis. In the case of an abnormal proximal migration of the patella cubiti, a ruptured triceps brachii tendon should be considered.