The intraoperative localization of residual parathyroid tissue during re-operations for persistent or recurrent secondary hyperparathyroidism (HPT) could have difficult due to cicatricial phenomena, anatomic modifications, ectopic or supernumerous glands. The use of intraoperative localisatin methods, as ultrasonographic and gamm-camera, permits a great level of success in identifying residual gland tissue. The Authors report their experience in the treatment of 5 cases of persisten HPT and 3 cases of recurrent HPT using gamma-camera and ultrasonography intraoperatively. Gamma-camera presented a sensitivity of 88% while ultrasonography did 100%. According to the experience, even numerically limited, of the Authors, intraoperative ultrasonography offers better results than gamma-camera, with less technical complexity.