We investigated the diagnostic values of microRNA-31 in peripheral blood mononuclear cells (PBMCs) for pediatric pulmonary tuberculosis in Chinese patients. Sixty-five children with TB were selected for this study, which was conducted at the Department of Infectious Diseases People’s Hospital of Laiwu City between December 2013 and December 2014. Sixty healthy children, selected in parallel, served as the control group. Real-time PCR was used to detect miR-31 expression in PBMCs. Serum levels of IL-6, TNF-α, NF-κB, and IFN-γ was detected by ELISA.