Various types of tumors, both benign and malignant, can be localized in the retroperitoneal space, which can develop not only in retroperitoneal organs, but also originate from nerves, connective or lymphatic tissue. Their pathomorphological diagnosis is relevant for the appointment of adequate treatment. There is a technique of percutaneous core-biopsy of such formations under the control of multispiral computed tomography, most often carried out by the "free hand" method. However, high radiation exposure not only to the patient, but also to the interventionist doctor are its negative sides. The author has developed a robotic device that automatically inserts a biopsy needle into the "place of interest". It was used for diagnostic punctures in the retroperitoneal space in 24 patients. In the control retrospective group, punctures were performed using the "free hand" method in 20 patients. The authors reveal an enhancement of the accuracy of puncture in the main group, a reduction in the amount of complications and of the duration of manipulation. The latter, along with the exclusion of radiation exposure to medical personnel, made it possible to reduce it on the subject.