Four randomized controlled trials, 1 double-arm comparative study, and 4 single-arm prospective studies were included in this investigation into the efficacy of hyaluronic acid (HA) injections for ankle osteoarthritis. A total of 354 patients were included throughout the studies. Pooled effect sizes indicated a significantly beneficial effect of HA compared to pre-treatment condition. Comparative analysis of HA against reference treatment tended to favour HA injection, although statistical significance was not exhibited. Furthermore, comparison to saline suggested that a placebo effect may be present with HA injections.