Rasamanikya is a herbo mineral preparation used extensively in Ayurvedic treatment. This is prepared using haratala (arsenic tri oxide) by the process of bhavana (wet trituration) and exposure to high temperature. This drug in minute quantities is said to be effective against respiratory ailments, skin diseases and fever. Rasamanikya was evaluated for safety in Wistar rats by sub acute (28 days) and chronic toxicity (90 days) studies. The test drug was given up to three times of its therapeutic dose orally. The test drug did not cause mortality or signs of toxicity in Wistar rats in both the studies. No major changes were observed with respect to hematology, and biochemical parameters. Post mortem of the animals did not reveal any gross pathology of internal organs. Histopathology changes observed in few groups were minimal and were of reversible type. Rasamanikya was found to be safe up to 54 mg/kg body weight in Wistar rats.