Abstract: Objective: This study was carried out to evaluate the acute and subchronic toxicities of Class Bitters® (CB)-a polyherbal formula prepared with Mondia whitei, Khaya senegalensis, Capparis erythrocarpus, Thonningia sanguinea and Xylopia aethiopica in male Wistar albino rats. Materials and Methods: Administration of 2000 mg kg-1 b.wt., of CB in an acute toxicity study recorded no mortality in rats within the observable period of 14 days. However, treatment of rats with CB at doses of 500 and 1000 mg kg-1 b.wt., respectively for 9 weeks in a sub-chronic study showed an increase in the daily consumption of feed and fluid intake in experimental rats. Results: A progressive increase in body weight was observed in rats administered with 500 and 1000 mg kg-1 b.wt., respectively during the exposure period. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), Alkaline phosphatase (ALP) activities and cholesterol level increased significantly (p≤0.05) in rats treated with 500 and 1000 mg kg-1 b.wt., respectively whereas a significant (p≤0.05) increase in the level of Triglyceride was only observed in rats treated with 1000 mg kg-1 b.wt. when compared with control. Total bilirubin and urea were significantly (p≤0.05) decreased while Creatinine showed no significant change. Histological examination of the liver and testes showed normal architecture in control group whereas hepatocytes of rats treated with 500 and 1000 mg kg-1 b.wt., respectively were characterized by chronic hepatitis. However, there were no observable pathological changes in the testes of rats in the experimental groups. Conclusion: These observations suggest that long term administration of CB may be toxic and its toxicity may be organ specific.