The purpose of this study was to evaluate the sensitivity, specificity, and predictive value of serum procalcitonin (PCT) for osteomyelitis and septic arthritis in children. PubMed, EMBase, and Cochrane Library were searched until 10 August 2021, for eligible literature focusing on PCT for the diagnosis of osteomyelitis and septic arthritis. Four articles with six studies were included in the diagnostic meta-analysis, a total of 654 children were examined for bacterial cultures in PCT, osteomyelitis, and septic arthritis. The results of diagnostic meta-analysis showed that the PCT had a sensitivity of 0.72, 95% confidence interval (CI) (0.65-0.79), specificity of 0.90, 95% CI (0.87-0.93), positive likelihood ratio (LR) of 3.87, 95% CI (2.53-5.90), negative LR of 0.39, 95% CI (0.22-0.70), and diagnostic odds ratio was 13.13, 95% CI (6.46-26.66), for the detection of osteomyelitis and septic arthritis using bacterial culture as the gold standard. Based on the summary receiver operating characteristic curve of PCT, it was found that the area under the curve of PCT was 0.88. In the evaluation of publication bias, the result of the regression line test showed that there was not publication bias (bias = 13.72; 95% CI, -1.84 to 29.28; P = 0.07). This study provided systematic review of the published literature on the diagnosis of osteomyelitis and septic arthritis in children using PCT, which may serve as a biomarker for diagnosis of osteomyelitis, but it has no direct evidences to support the diagnosis of septic arthritis. However, the specific optimal cutoff value of PCT and specific population still needed to be verified by large sample studies.