Background: Tartrazine is the most widely employed dye in food stuffs, medicines as well as cosmetics. Objective: This study aimed to assess oral sub-chronic toxicity of tartrazine on the body weight, heart and brain of adult male albino rats using biochemical and histological studies and to evaluate the potential protection function of vitamin E. Methodology: This controlled clinical trial study included 24 rats. They were randomly processed into four groups: control, vitamin E (100mg/kg/day), tartrazine (300 mg/kg/day), tartrazine + vitamin E groups. The treatment was given to all rats orally for 30 days. Weights of body, heart and brain, serum levels of Cardiac Troponin I (cTnI), Lactate Dehydrogenase (LDH) and Creatinine Kinase muscle-brain (Ck-MB), Superoxide Dismutase (SOD),Catalase (CAT) and histological changes of heart and brain were assisted. Results: There was a significant increase in weights of body, heart and brain, cTnI, LDH and CK-MB levels, also a significant decrease in SOD and CAT activities and alternation in the normal histological structure of the heart and brain in the tartrazine group in comparison to the control group. Vitamin E co-administration with tartrazine produced an improvement in all previous changes caused by tartrazine. Conclusion: The present study concluded that tartrazine has a toxic effect on the heart and brain. The use of vitamin E via its antioxidant properties leads to improvement of such toxicity.