Background: The aim of this study is to assess the clinical effectiveness and safety of hyaluronic acid gel for the prevention of postoperative intrauterine adhesions (IUAs). Methods: PubMed, Cochrane Library, Embase and ClinicalTrials.gov databases were searched for randomized controlled trials. Results: Six RCTs with a total of 564 patients met the inclusion criteria. The meta-analysis showed that, compared to no other treatment method, hyaluronic acid gel significantly reduced the rate of any IUA (risk ratio [RR] 0.68; 95% CI 0.53–0.86; p = 0.03; I<sup>2</sup> = 64%) and adhesion score (standard mean difference = –2.90; 95% CI –4.61 to –1.49; p < 0.00001; I<sup>2</sup> = 98%) following intraperitoneal or intrauterine surgery. Treatment lowered the rate of IUAs classified as moderate (RR 0.26; 95% CI 0.13–0.52; p = 0.13; I<sup>2</sup> = 0%), but not those deemed mild (RR 0.86; 95% CI 0.62–1.21; p = 0.39; I<sup>2</sup> = 3%) or severe (RR 0.33; 95% CI 0.03–3.09; p = 0.33; I<sup>2</sup> = 0). Compliance with hyaluronic acid gel treatment was low. Conclusion: Hyaluronic acid gel can prevent IUAs, particularly those with moderate severity and a lower adhesion score.