Osteoradionecrosis (ORN), which is a serious complication and late toxicity of radiotherapy, has been reported in proton therapy. This meta-analysis included 17 original studies and reported the pooled grade ≥3 ORN rate of 0.01. The pooled incidence rate of grade ≥1 ORN was 0.05 and grade ≥2 ORN was 0.03. A previous study showed that the grade ≥3 ORN rate in the IMRT is about 1.5 %. This analysis showed that ORN rate is similar in proton-based radiotherapy and photon-based radiotherapy.