Introduction: Phosphodiesterase type 5 inhibitors (PDE5i) are the first-line treatment for erectile dysfunction (ED) however, some patients experience inadequate therapeutic responses. Low-intensity extracorporeal shockwave therapy (Li-ESWT) has emerged as a restorative treatment that may enhance erectile function and responsiveness to PDE5i. This systematic review evaluated the efficacy and safety of Li-ESWT alone or in combination with PDE5i compared with relevant monotherapy. Methods: PubMed, Scopus, ScienceDirect, Europe PMC, and Epistemonikos were systematically searched for English-language studies published between 2015 and 2026. RCT and comparative observational studies evaluating Li-ESWT alone or combined with PDE5i in adult men with ED were included. Erectile function, safety, and secondary clinical outcomes were narratively synthesized because of clinical and methodological heterogeneity. Risk of bias was assessed using RoB 2 and ROBINS-I. Results: Five studies (420 participants; three RCTs and two prospective non randomized studies) were included from 492 identified records. Li-ESWT consistently improved erectile-function outcomes. Compared with relevant monotherapy, combination therapy generally produced greater improvements in IIEF-5/IIEF-EF and EHS in selected populations, while another suggest greater durability in treatment effects. Benefits appeared more pronounced in moderate to-severe ED, whereas Li-ESWT monotherapy may be sufficient in milder disease. Li-ESWT demonstrated short-term efficacy comparable to PDE5i monotherapy, with potential advantages in tolerability and treatment satisfaction. All RCTs had some risk-of-bias concerns, while both non-randomized studies had serious overall risk of bias. Conclusion: Li-ESWT-based combination therapy may provide greater improvements in erectile-function outcomes than monotherapy in selected patients; however, heterogenity in populations, treatment protocols and methodological limitations precludes definitive conclusions regarding its superiority, particularly in strictly defined PDE5i-refractory ED.