Background: Robot-assisted radical prostatectomy (RARP) including pelvic lymph node dissection (PLND) is the current state of the art in surgical therapy of localized prostate cancer with intermediate or high risk. PLND in particular is associated with morbidity inherent to this method; the rate of symptomatic lymphoceles (sLCs), for example, ranges up to 10%. Objective: Various intraoperative modifications have been developed with the aim of reducing the sLC rate. Based on current studies, a peritoneal interposition flap (PIF) appears to be one of the most effective methods for this purpose. Under the criteria of a systematic review, 5 retrospective studies have been identified until now, 4 of which showed a positive effect of PIF on the sLC rate. Results and Limitations: A total of 1,308 patients were included in the aggregated analysis of these 5 studies. The amount of sLCs was 1.3% (8/604) and 5.7% (40/704) in the PIF and standard groups, respectively (p < 0.001). The resulting odds ratio (OR) was 0.23 (95% confidence interval [CI]: 0.05–0.99), taking into account a noteworthy heterogeneity of the 5 studies (Q = 9.47, p = 0.05; I<sup>2</sup> = 58%). In addition, a prospective randomized and blinded study (Pianoforte trial) with corresponding sLC rates of 8.3% (9/108) versus 9.7% (12/124) (p = 0.820) exists. In this study, the OR was 0.85 (95% CI: 0.34–2.10, p = 0.722). Conclusion: Despite positive results from retrospective studies with indirect evidence, the role of the PIF in the reduction of sLC in RARP could not be conclusively assessed yet. The results of the first prospective randomized study do not show a positive effect of PIF, declaring a research gap for further studies with direct evidence.