Material and methods. Robot-assisted operations for non-organ retroperitoneal tumors were performed in 20 patients. The biggest tumor’s diameter was 160 mm, the smallest — 32 mm, mean value was 79.1±37.8 mm. According to morphological investigation data lymphangioma was diagnosed in 4 (20%) patients, lipoma — in 3 (15%) cases, peritoneal cyst — in 2 (10%) patients. Solitary lymphatic node, teratoma, leiomyosarcoma, accessory stomach, bronchogenic cyst, adenogenous cancer, ureterocele, megaureter, schwannoma, leiomyoma, malignant paraganglioma were observed in 1 (5%) case respectively. Results. Surgery duration was 138±55.9 min. Blood loss was 69±112.7 ml (range 0—500 ml). Intraoperative complications (bleeding) were diagnosed in 3 (15%) patients. There were no conversions. Robot-assisted variant has been demonstrated in case of non-organ retroperitoneal tumors with diameter not more than 100—120 mm.