BackgroundPlatelet-rich plasma (PRP) injection for ankle osteoarthritis (OA) treatment showed contradictory results. This review was aimed to pool individual studies which assessed the efficacy of PRP for ankle OA treatment.MethodsThis study was conducted following the preferred report items of systematic review and meta-analysis guideline. PubMed and Scopus were searched up to January 2023. Meta-analysis, or individual randomised controlled trial (RCT), or observational studies were included if they involved ankle OA with aged ≥ 18 years, compared before–after receiving PRP, or PRP with other treatments, and reported visual analog scale (VAS) or functional outcomes. Selection of eligible studies and data extraction were independently performed by two authors. Heterogeneity test using CochraneQtest and theI2-statistic were assessed. Standardised (SMD) or unstandardised mean difference (USMD) and 95% confidence interval (CI) were estimated and pooled across studies.ResultsThree studies from meta-analysis and two individual studies were included, which consisted of one RCT and four before–after studies with 184 ankle OAs and 132 PRP.The average age was 50.8–59.3 years, and 25–60% of PRP injected cases were male. The number of primary ankle OA was accounted to 0–100%. When compared to before treatment, PRP significantly reduced VAS and functional score at 12 weeks with pooled USMD of − 2.80, 95% CI − 3.91, − 2.68;p< 0.001 (Q= 82.91,p< 0.001;I296.38%), and pooled SMD of 1.73, 95% CI 1.37, 2.09;p< 0.001 (Q= 4.87,p= 0.18;I238.44%), respectively.ConclusionPRP may beneficially improve pain and functional scores for ankle OA in a short-term period. Its magnitude of improvement seems to be similar to placebo effects from the previous RCT. A large-scale RCT with proper whole blood and PRP preparation processes is required to prove treatment effects.Trial registrationPROSPERO number CRD42022297503.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13018-023-03828-z.