Erectile dysfunction (ED) is a well-known complication of radical prostatectomy (RP). Oral 5-phosphodiesterase inhibitors are currently the most widely used penile rehabilitation treatment for ED following RP, but they are less effective than for those with general ED. Low-intensity extracorporeal shock wave treatment (LI-ESWT), causing a biological change that induces neovascularization, has recently been used as a treatment for ED. Therefore, we conducted a systematic review and meta-analysis to investigate the efficiency of LI-ESWT in ED following RP. PubMed, Embase, and the Cochrane Library were searched up until December 2021. The endpoint was the change in IIEF scores after LI-ESWT. Five papers (460 patients) were included in the final analysis. In IIEF scores performed 3–4 months after LI-ESWT, the group receiving LI-ESWT showed statistically significantly better results than the control (WMD = −2.04; 95% CI, −3.72 to −0.35; p = 0.02). However, there were a total of two studies that measured the results after 9–12 months. There was no statistical difference between the two groups (WMD = −5.37; 95% CI, −12.42 to 1.69; p = 0.14). The results of this analysis indicate that LI-ESWT showed a statistically significant effect on early recovery in penile rehabilitation of ED following RP. However, the level of evidence was low. Therefore, careful interpretation of the results is required.