Senna (Cassia angustifolia Vahl.) is widely used as laxative, but data from Ames test and animal and/or human studies with this agent have shown a mutagenic and carcinogenic potentiality. Using thee experimental models (bacterial inactivation test; bacterail mutagenisis assay-Mutoxitest; and growth Inhibition test, we investigated the toxicity of senna. Our data suggest an absence of mutagenic and citotoxic potentiality of senna.