Toxicological screening is a paramount need for developing new drugs or providing a safety profile for existing traditional medicine. Metals and minerals that are transformed into drugs must have excellent therapeutic efficacy and safety. It is essential to evaluate the margin of safety between the dose level that exerts the therapeutic effect and adverse effect to provide benefit to risk assessment. The present study aims to establish the safety of the Ayabrungaraja karpam (ABK), a herbometallic Siddha drug by 28 days repeated dose sub-acute toxicity study. In this study, 70 healthy young wistar albino rats (Rattusnorvegicus Sp.) of both sex between 8-12 weeks of age and weighing 150 -175g were studied. Among them 30 rats were divided into 3 groups of n=10 and administered with ABK at the dose of 250, 500, and 1000 mg/kg body weight respectively. The control group n=10, vehicle control group n=10, satellite vehicle control n=10, satellite high dose group n=10 received distilled water and lime juice and ABK at the dose of 1000mg/kg b.w respectively. Satellite group was pre set to determine the reversibility or recovery from toxic effect. All the groups received same water and food. No observation made on behavioural changes. All the wistar albino rats were alive until the study ended. Prominent pathological changes were not observed during 28 days repeated dose and reversal toxicity study in haematological, biochemical and histopathological investigations in both sexes of wistar albino rats treated with Ayabhringraja Karpam. Ayabhringraja Karpam in different concentrations was found to be completely safe and non-toxic under sub-acute toxicity studies.It is recommended to do further study on subchronic or chronic toxicity study.