Introduction. Prostate cancer (PC) ranks second in the structure of male malignancies. Radical prostatectomy is the gold standard for the treatment of PC. There are various surgical approaches: open, laparoscopic, and robot-assisted ones. Currently, robot-assisted radical prostatectomy (RARP) employing the Da Vinci robotic system, is increasingly being used; it is successfully applied to patients with the nonstandard clinical course of PC. Objective — to assess the oncological and functional outcomes of RARP according to prostate volume. Subjects and methods. The case histories of 50 patients were retrospectively analyzed. All the patients were divided into 2 groups: 1) 25 PC patients with a prostate volume of no more than 80 cm3; 2) 25 PC patients whose prostate volume above 80 cm3. The investigators estimated the following indicators: time of surgery, volume of blood loss, the number of intra- and postoperative complications according to the Clavien—Dindo classification, length of postoperative hospital stay, results of postoperative morphological studies, and oncological and functional outcomes. The urinary retention function was evaluated from the results of the daily pad test, the IPSS questionnaire, and the quality of life (QoL) assessed from the presence of urination disorders before and 6—12 months after surgery. The 5-Item version of the International Index of Erectile Function (IIEF-5) questionnaire was used to identify erectile dysfunction and its degree. Results. Comparing the two groups showed statistically significant differences in the time of surgery and the volume of blood loss. The average duration of surgery was 186±52.5 (from 110 to 265) minutes in Group 1 and 202.2±56.6 (from 120 to 300) minutes in Group 2. Blood loss was 172 (from 50 to 500) ml in Group 1 and 232 (from 50 to 1000) ml in Group 2. At 3 months after surgery, a biochemical recurrence was recorded in one patient from Group 1. Two-year overall and cancer-specific survival was 100% in both groups. Conclusion. RARP can be successfully used to treat PC in patients, regardless of the initial prostate volume.