Aim: In siddha system of medicine, one of the typical kantham formulation is ‘Kumaara veeriya kaantha chenduram’ (KVKC) which is indicated for anaemia. The toxicological study of the drug was not reported. The objective of this study is to evaluate its safety by performing repeated dose 90-day oral toxicity studies as per OECD test guidelines 408 for the further clinical application in anaemia cases. Methods: In this study KVKC was administered in wister albino rats orally at low dose 100 mg/kg/ b.wt, Mid dose 200 mg/kg/b.wt, High dose 400 mg/ kg/ b.wt once a day for 90 days with honey. Animals were observed for toxic signs for 90 days. On 91st day cage side observations, hematological, biochemical and histopathological analysis were executed to recognize the toxic effects. Results: Results of the hematological, biochemical and histopathological analysis conducted on 91th day revealed that there were no significant changes in all the drug treated animals when compared with those of respective controls. According to these results, Kumaara veeriya kaantha chenduram could be concluded as no-observed-adverse-effect level (NOAEL). Conclusion: This study provides scientific validation for the drug’s safety and also proved its effectiveness in long-term administration without harming the human being. And the drug KVKC is safe in the dose of 260 mg for human adult mentioned in the siddha literature.