Erectile dysfunction (ED) is common in patients with pelvic fractures associated with urethral injury (PFUI). We aim to assess the efficacy and safety of low-intensity shock wave therapy (LiSWT) in ED treatment related to PFUI. Forty-three consecutive patients with PFUI who underwent surgical repair between January 2014 and March 2017 were sampled in Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. ED onset following surgical repair was initially treated with oral phosphodiesterase type 5 inhibitors (PDE5i) for six months. PDE5i non-responders were referred for LiSWT of six weekly sessions. Erectile function was evaluated by the International Index of Erectile Function-5 (IIEF-5) and Erection Hardness Score (EHS). Forty-three consecutive patients were enrolled in our study. ED was observed in 79.1% (34/43) patients following surgical repair. These 34 patients were given oral PDE5i (Tadalafil® 5 mg) daily treatment, 64.7% (22/34) patients restored erectile function to normal range (EHS: 3.4 ± 1.3, IIEF-5: 21.7 ± 1.0). The other twelve PDE5i non-responders were referred for LiSWT. Seven patients (58.3%, 7/12) remained unable to maintain the rigidity for full sexual intercourse. The other five patients reported allowing full sexual intercourse. Based on our results, LiSWT may ameliorate the ED in men with PFUI and shift PDE5i non-responders to responders.