In India, natural preparations derived from plants are widely used for the treatment of various diseases. Hence it becomes necessary to assess the modulating action of the plant extracts when associated with other substances. Ethinylestradiol is not only a genotoxic agent but also a tumor initiating agent. It is widely used in oral contraceptive formulations and also for the treatment of various sexual and metabolic disorders. In the present study, the antigenotoxic effect of Eclipta alba was evaluated against the genotoxic effect induced by 10 μM of ethinylestradiol in the presence of metabolic activation using mitotic index (MI), chromosomal aberrations, sister chromatid exchanges and replication index (RI) as parameters. The treatment of 10 μM of ethinylestradiol along with 1.02x10–4, 2.125x10–4, 3.15x10–4 and 4.17x10–4 g/mL of Eclipta alba (E. alba) extract in culture medium results in a significant dose dependent decrease in the genotoxic effects induced by the treatment of 10 μM of ethinylestradiol. The results of the present study suggest that the plant extract per se does not have genotoxic potential, but can modulate the genotoxicity of ethinylestradiol in cultured human lymphocytes.