The thymus is a primary lymphoid organ responsible for the selection, maturation, and expansion of T lymphocytes, which are essential for immune defense. The thymic microenvironment consists of a three-dimensional network mainly formed by epithelial cells. These cells secrete substances necessary for the proliferation, differentiation, selection, and maturation of thymocytes (T cell precursors). Throughout life, the thymus undergoes atrophy (thymic involution), reducing its original functions. This involution is associated with oxidative processes and epithelialmesenchymal transition (EMT), in which epithelial cells lose their functions and are converted into mesenchymal cells. Transforming growth factor beta 1 (TGF-β1) is a protein capable of inducing EMT. Studies have shown that antioxidants such as resveratrol (RSV) can delay thymic involution. Therefore, this project evaluated whether resveratrol could attenuate EMT and oxidative stress induced by TGF-β1. For this purpose, in vitro cultures of thymic epithelial cells (THPN cell line) were treated with resveratrol and/or TGF-β1 at different concentrations. To verify EMT occurrence, morphological analyses, flow cytometry assays with FVS and vimentin markers were performed to assess cell viability and mesenchymal phenotypes, respectively. The analyses revealed morphological changes, as cells treated only with TGF-β1 were more elongated compared to the control and TGF-β1 + RSV groups, suggesting EMT occurrence. The FVS marker indicated that RSV concentrations above 6.25 µM reduced cell viability. Furthermore, 24h treatments resulted in higher cell viability compared to 48h, possibly due to cytotoxic effects. Increased vimentin expression in the TGF-β1 group confirmed EMT induction and morphological alterations, whereas RSV attenuated and even reversed these changes. Thus, the results suggest that RSV reduces EMT occurrence, and lower concentrations of this antioxidant allow greater cell viability.