ObjectiveTo systematically review the correlation of pSTAT3 overexpression and prognosis in lung cancer patients.MethodsWe searched from PubMed, EMbase, Web of Science, CNKI, VIP and WanFang Data databases to collect relevant studies about the correlation of pSTAT3 overexpression and prognosis in lung cancer patients from inception to November 2016. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed by using RevMan 5.2 software.Results A total of thirteen studies were enrolled. The results of the meta-analysis showed that the overall survival (HR=1.23, 95%CI 1.04 to 1.46, P=0.02) of pSTAT3 overexpression group was shorter than that of low expression group. In terms of clinical prognostic characteristics, pSTAT3 overexpression rate in stage Ⅲ to Ⅳ group was significantly higher than stage Ⅰ to Ⅱ (OR=1.92, 95%CI 1.13 to 3.27, P=0.02). pSTAT3 overexpression rate of lung cancer patients with lymphatic node metastasis was also significantly higher than lung cancer patients without lymphatic node metastasis (OR=1.81, 95%CI 1.20 to 2.72, P=0.004). However, there was no statistical difference of pSTAT3 overexpression between well-moderately differentiation and poorly differentiation group (OR=0.82, 95%CI 0.44 to 1.53, P=0.54).ConclusionpSTAT3 overexpression is associated with poorer overall survival of lung cancer patients, as well as with more and advanced TNM grade and lymph node metastasis. It may be an indicator poor biomarker in lung cancer patients. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusion.