Abstract: The safety of rosiglitazone as it pertains to the cardiovascular system has been continuously debated. Because there is no strong evidence of an increased risk of myocardial infarction or cardiovascular mortality with rosiglitazone. This study aimed to investigate different doses of rosiglitazone effects to treat myocardial infarction in animal model specifically rats induced with isoperetenol used a high and low doses (6 and 12 mg kg-1) determined the greatest influence and compare between doses. Spectrophotometric and chemical methods measured parameters specific to myocardial infarction presented a significant accumulation of lipid peroxidase, reduction of glutathione and increased of reduced lactate dehydrogenase levels were observed while the cardiac marker enzymes creatinine kinase, aspartate aminotransferase and alanine aminotransferase. None of these parameters changed significantly with rosiglitazone treatment (6 and 12 mg kg-1) when compared to the group that was only treated with isoproterenol. Present results suggest that rosiglitazone does not potentiate the cardiac toxicity of isoproterenol-induced myocardial infarction in rats. These findings strengthen the notion that rosiglitazone has a lower risk of myocardial infarction than previously reported.