Objective: Hyperbaric oxygen therapy (HBOT) is used for the treatment of chronic diabetic foot ulcers (DFUs); however, the available evidence regarding its benefits is based on prospective or cross-sectional studies. We conducted a meta-analysis of randomized controlled trials to assess the efficacy of HBOT in improving wound healing and reducing the need for major amputation in patients with chronic DFUs. Methods: We reviewed PubMed, Web of Science and the Cochrane Library for reports published up to April 2019. Results: Six studies evaluating healed ulcers and 4 studies evaluating major amputation. There was a trend of increasing proportion of ulcers, as shown by a pooled RR of 3.6 (95% CI 0.99 to 13.20). HBOT did not reduce the amputation rate. Subgroup analysis showed that HBOT facilitated wound healing and reduced the amputation rate in a subgroup of patients with a duration of diabetes of ≤ 16 years, with an estimated RR of 26.96 (95% CI 3.84 to 189.02) and 0.18 (95% CI 0.07 to 0.477), respectively. No beneficial effects were found for patients with duration of diabetes of > 16 years Conclusion: HBOT facilitates wound healing and reduces the amputation rate in patients with duration of diabetes of ≤ 16 years.