The aim of this paper was to evaluate the potential in vitro antioxidant activity of Tynanthus micranthus Corr. Mello ex Schum and its activity on tyrosinase, a melanogenesis-involved enzyme. The methods employed were 2,2-diphenyl-1-picril-hydrazyl (DPPH), phosphomolybdenum complex, catalase, peroxidase, superoxide dismutase (SOD), reduced glutathione (GSH) and mushroom tyrosinase activity assay, against the activity of the remaining hydroalcoholic fractions of the leaves (HLF), stems (HSF), and roots (HRF). The results showed that the HLF protected erythrocytes against oxidative stress and did not lead to oxidation of the cellular system, maintaining normal levels of SOD and GSH, with effect similar to catechin and quercetin used as standards. HLF also led to stimulation of tyrosinase enzyme, when compared with the control. It is thus concluded that the HLF has antioxidant potential and may be used in studies involving the development of drugs for hypopigmentation diseases.