A rare case of patella tuberculosis is reported. Clinical signs comprised chronic inflammatory pain, knee swelling and joint stiffness, with two years’ evolution. Standard X-ray showed focal osteolysis with intact joint line. Diagnosis was based on surgical biopsy during arthrotomy. Treatment comprised nine months’ antibiotherapy and bone curettage to prevent intra-articular extension. At 42months’ follow-up, functional results were good, without recurrence of infection.