We have developed an image-based human-machine interface that tracks the surgeon’s face robustly in real-time(30Hz) and does not require to use any body-contacted sensing devices. Based on this face tracker we have developed a new robotic laparoscope positioning system for solo surgery. Our system completely frees the surgeon’s hands and feet from the laparoscope guiding task. To evaluate the performance of the proposed system and its applicability to clinical use, an in vivo experiment was carried out in which a surgeon used the system to perform a laparoscopic cholecystectomy on a pig.