Eight cases of primary tumors of the patella were identified in a consecutive series of 587 patients treated surgically for benign or malignant bone tumors. Six cases were benign (5 giant cell tumors and 1 chondroblastoma), and there were 2 malignant tumors (osteosarcoma and malignant fibrous histiocytoma). Both patients with malignant lesions had Rothmund-Thomson syndrome. Benign pulmonary metastases developed in 2 of the patients with giant cell tumor and 1 patient now is deceased 72 months after surgery. Two patients were treated before referral to a tertiary care center; 1 with patellectomy before histologic diagnosis and 1 with curettage. Both resulted in extension of disease into the knee joint. Tumors of the patella require careful assessment before surgical management. Conservation of the bone can be achieved in benign lesions that have adequate residual bone remaining at the articular surface. Conservation of the extremity is possible in malignant tumors, but reconstruction of the extensor mechanism is difficult.