Purpose To compare surgical results, morbidity and positive surgical margins rate of patients undergoing robotic partial nephrectomy (RPN) versus open partial nephrectomy (OPN). Methods This is an observational multicenter study promoted by the ''Associazione GIovani Laparoscopisti Endoscopisti'' (AGILE) no-Profit Foundation, which involved six Italian urologic centers. All clinical, surgical, and pathological variables of patients treated with OPN or RPN for renal tumors were gathered in a prospectively maintained database. Tumor nephrometry was measured with PADUA score, and complications were stratified with modified Clavien system. Differences between RPN and OPN group were assessed with univariate analysis. Perioperative variables independently associated with complications were assessed with multivariate analysis. Results A total of 198 and 105 patients were enrolled in OPN and RPN group, respectively. Both had similar demographics, indications to surgery, tumor nephrometry, renal function, WIT (18.7 vs. 18.2 min; p = NS), positive margin rate (5.6 vs. 5.7 %; p = NS), intraoperative complications, and postoperative medical complications. Compared to OPN, RPN group was significantly more morbid (p = 0.04), included tumors with smaller size (p = 0.002), had longer operative time (p \ 0.001), lower blood loss, surgical postoperative complications (5.7 vs. 21.2 %, p \ 0.001), Clavien 3-4 surgical complications (1 vs. 9.1 %, p = 0.001), and shorter hospitalization. The surgical approach resulted independently correlated with surgical complications on multivariate analysis. Conclusion In the present series, RPN was associated with a significant reduction of blood loss, surgical complications, including the reintervention rate for urinary fistula and postoperative bleeding, and with a shorter hospitalization.