The purpose of this systematic review and meta-analysis was to identify association between the level of transforming growth factor-β (TGF- β) expression in endometrial tissue, serum, peripheral blood, peritoneal fluid, peritoneum from women with endometriosis. Search was conducted in electronic databases including PubMed, The Cochrane Library, ClinicalTrials.gov, Embase, MEDLINE, Web of Science. Ten non-randomized controlled studies comparing the level of TGF- β in women with laparoscopically confirmed endometriosis and comparison group were included in quantitative synthesis. Risk-of-bias assessment tools recommended by the Cochrane Society were used to evaluate the risk of bias in the studies included. Our systematic review and meta-analysis showed that the level of TGF- β in samples from women with endometriosis is higher. However, the main limitation of our study is a high heterogeneity of published data, which was analyzed. Hence, further research is needed to provide more data with common outcomes and highlights on how to manage and treat health conditions driven by TGF- β activation and fibrosis, in particular, endometriosis.