Prostate cancer (PCa) is the most common solid neoplasm diagnosed in developed countries. Nerve-sparing radical prostatectomy (NS-RP) has been widely accepted as the best choice treatment for localised PCa. However, erectile dysfunction (ED) and urinary incontinence are commonly observed after NS-RP. Using meta-analysis, we examined if phosphodiesterase type 5 inhibitors (PDE5-Is) could improve the symptoms of ED in patients undergoing NS-RP. This review contained seven randomised placebo-controlled trials with a total of 2,655 male patients. Patients in PDE5-Is group showed significant improvement in the International Index of Erectile Function-Erectile Function domain score (IIEF-EF), Global Assessment Questionnaire (GAQ), Sexual Encounter Profile question 2 (SEP-2) and SEP-3. Although the incidence of treatment-emergent adverse events (TEAEs) were high in both groups (56.44% vs. 40.63%), the safety profile were acceptable, with low incidence of discontinuation rate due to adverse events. Therefore, PDE5-Is are recommended for the treatment of post-NS-RP ED. Patients should be informed of possible adverse events.