The aim of the present study was to perform a systematic review of the literature regarding the effect of different mouthwashes on gingival healing after oral surgery in adults. Searches were conducted in seven databases (PubMed/MEDLINE, Cochrane Library, Clinical Trials Registry, Embase, LILACS, Web of Science, and Google Scholar) for relevant randomized controlled trials (RCTs) published up to April 2022. The selection of studies, data extraction, and risk of bias appraisal were performed independently by two reviewers, and a third researcher was consulted to resolve disagreements. Data syntheses were presented narratively for the different criteria of gingival wound healing. Among 4502 articles retrieved from the databases, 13 studies met the eligibility criteria and were included in the present review. Chlorhexidine was the most frequent mouthwash studied (eight studies) and was used in different concentrations and combinations. Cetylpyridinium chloride, H2 Ocean Sea Salt, Commiphora molmol 0.5%, chlorhexidine 0.12%, and essential oils reported better healing than a negative control. However, the uncertain risk of bias in most RCTs included in this review precludes definitive conclusions. Well-designed RCTs are therefore still needed in this area.