Extraperitoneal pelvioscopy is a surgical endoscopy without insufflation which enables exploration of the extraperitoneal space in order to obtain biopsy specimens of adenopathies and tumors. 189 extraperitoneal endoscopy have been performed since 1976. When made through an iliac approach, the Extraperitoneal Endoscopy explores iliac and pelvic lymph nodes. It is an indication when checking the extension of uterine, prostatic and bladder cancers. Recently, a system of computerized assistance has been added to the initial method. Its aim is to guide the movements of the surgical tool when the indication is difficult: overweight patient, small tumors, risky tumoral environment. The basic principle is to show recalculated RMI or CT scan sections of the patient during the intervention, on which appear in real time the positions of the endoscope and that of the target to biopsy. The authors describe the technical ways of the method, the system of tridimensional localisation included in the operating room and the sort of interface given to the surgeon. In the future, the realisation of a simulator of intervention will allow diffusion and teaching of this intervention.