Introduction: Presence of heavy metals (like Mercury, Arsenic, Lead etc.) in Ayurvedic formulations became a major concern in current scenario. Therapeutic use of these formulations since ages without any noticeable side effects is ultimate proof for their safety. Considering the growing concerns, it becomes necessity to prove their safety and efficacy to generate scientific evidences. This can also be possible through animal experiments. The present study is carried out to evaluate the effect of Rasamanikya (RM), an arsenical preparation, in different dose levels on ponderal, hematological and biochemical parameters in Charles foster strain albino rats. Methods: RM was prepared as per classical guidelines and administered to Charles foster albino rats at 12mg/kg and 24mg/kg for 90 consecutive days followed by 30 days recovery. Blood was collected and rats were sacrificed on 91th day. Ponderal, hematological and biochemical parameters were studied. Results: Results showed significant increase in eosinophil counts, decrease in HDL and albumin at both dose levels. Comparatively, all the differences in between the groups are insignificant and no pathological changes at ponderal, hematological and bio-chemical levels were observed. Conclusion: Rasamanikya has potential to generate hematological and biochemical alternations on long standing usage. Hence, mandatorily be used under strict supervision of an Ayurvedic physician.