Objectives: Robotic-assisted partial nephrectomy (RAPN) is preferred to radical nephrectomy because it guarantees superior functional outcomes in patients with small renal masses (RMs). Only a few studies so far have evaluated the feasibility of RAPN for the treatment of RM 4cm. The aim of this study is to evaluate the safety and feasibility of RAPN based on a comparison of trifecta and pentafecta rates for RMs 4cm. Material and Methods: We retrospectively analyzed prospectively collected data from an institutional database of patients undergoing RAPN from September 2013 to November 2016. Demographic and perioperative data were collected and statistically analyzed. Pentafecta is defined as achievement of trifecta (negative surgical margins, no postoperative complications, and warm ischemia time 25 minutes) with the addition of two other variables, namely, over 90% estimated glomerular filtration rate preservation and no chronic kidney disease stage progression 1 year after surgery. Results: Overall, 123 patients underwent RAPN. Of those, 38 (30.9%) had RMs 4cm. Trifecta was achieved in 72.9% of patients with RMs <4cm and in 44.7% of those with 4cm, whereas pentafecta was achieved by 23.5% of patients with RMs <4cm and by 10.5% of those with RMs 4cm. No significant predictive factors were found in connection with trifecta, whereas only one was found in connection with pentafecta, namely, age (odds ratio: 0.91; 95% confidence interval 0.85-0.98; P=.01). Conclusions: RAPN may be considered a feasible and safe surgical approach ensuring good functional outcome even for patients with RMs 4cm. Pentafecta rates after RAPN were comparable between RMs <4 and 4cm in diameter.