Bhasmas are unique Ayurvedic metallic preparations used for medicinal purposes since ancient times. With increasing knowledge of risk of nanomaterials, it becomes imperative to assess the safety of nanoparticulate Ayurvedic medicines using toxicity models. In this study, zinc bhasma was characterized using modern physicochemical techniques. In vitro toxicity test revealed no major cytotoxicity at all the dose levels tested. No behavioral abnormality, clinical signs and mortality was seen indicating no adverse effects. SGOT, SGPT and serum urea were also not significantly altered indicating no major organ toxicity. In the current study, zinc bhasma appears safe for human use.