Background/Aim:Doxorubicin (Dox) is one of the anthracyclines which are a group of antibiotics that are among the most active chemotherapeutic agents. It has a cardiotoxic effect. The objective of the study was to evaluate Dox as chemotherapeutic agent with cardiotoxic effect. Methods: forty male wistar rats (200 ± 50 g) were divided in to two groups: control and doxorubicin. Doxorubicin group was injected at a dose of 3 mg/kg BW of doxorubicin at days 1, 3, 5, 7, 9 and 11. At 12th dayof the study, blood was collected by retro-orbital puncture and serum LDH and CK-MB were estimated. The animals were then sacrificed and their hearts were dissected and specimens were prepared and stained for histological examination by light microscope. Results: Examination of H&E sections of the left ventricular myocardium of Dox-treated group showed irregular separated cardiomyocytes with pyknotic nuclei and hemorrhage in-between. Sections of the same group revealed weak positive cytoplasmic immunoreactions for desmin protein in numerous cardiomyocytes. Intercalated discs and cytoplasmic striations also disappeared in several cardiomyocytes. Ultrathin sections of left ventricle of the Dox-treated group exhibited cardiomyocytes with irregular fragmented shaped nucleiand peripheral condensed chromatin with disorganized intercalated discs.Variable sized mitochondria with ruptured cristae were observed in between the fragmented myofibrils. Conclusion: Dox showed evident harmful effects on left ventricular cardiocytes of adult male albino rats. Therefore, searches are required to find an alternative drug with the same efficacy or exploring protective methods against Dox hazardous impact on the heart.