Background: Postoperative inguinal hernia (IH) is a non-negligible sequelae with a wide array of rates after robot-assisted laparoscopic radical prostatectomy (RALP). Our aim was to evaluate the incidence and risk factors of postoperative IH development in men undergoing RALP., Methods: A retrospective analysis of 839 patients "541 of conventional-RALP (C-RALP), and 298 of Retzius sparing-RALP (RS-RALP)" received treatment of prostate cancer between 2005 and 2016 and met with our inclusion criteria was performed. Primary endpoint was incidence of IH after RALP, while secondary endpoint was to assess risk factors of IH occurrence., Results: Overall incidence of postoperative IH was 6.3% (53 out of 839). Mean follow-up period and median time of IH development were 24.1 and 14.0 months, respectively. Among patients who developed IH, there was a higher incidence in C-RALP compared to RS-RALP, (79.2 vs 20.8%, respectively, P = 0.02). Multivariate analysis showed that BMI group (HR 0.471, P = 0.023) and C-RALP (HR 2.834, P = 0.002) were significant predictors of IH development. Kaplan-Meier curve showed that 3-year IH-disease progression free rate was significantly higher after RS-RALP compared to C-RALP (94.2 vs 71.6%, respectively, P < 0.001), likewise in obese versus non-obese patients (87.7 vs 76.6%, respectively, P < 0.003)., Conclusion: Our study showed that overall incidence of IH was 6.3% after RALP. Nevertheless, RS-RALP carries a lower incidence of IH after surgery, while C-RALP and low BMI are predictors of IH development.