The present study was conducted with the aim of evaluating the protective effects of Bom- byx mori, quercetin and benazepril on doxorubicin (DXR) induced cardiotoxicity and nephrotoxi- city in rats. B. mori, quercetin and benazepril were administered for 7days, and a single intravenous injection of 10 mg/kg body weight of DXR on day five. The animals were sacrificed 48 h after DXR administration. DXR produced a significant elevation in the malondialdehyde (MDA) level and significantly inhibited the activity of glutathione (GSH) in the heart and the kidney followed by the activity of catalase (CAT) in the heart tissue with a significant rise in the serum levels of aspartate transaminase (AST), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), creat- inine and a reduction in serum GSH levels indicating acute cardiac toxicity. B. mori, quercetin and benazepril pretreatment significantly reduced the MDA concentration and ameliorated the inhibi- tion of cardiac GSH and CAT activity. B. mori, quercetin and benazepril also significantly improved the serum levels of AST, LDH, BUN, creatinine and GSH in DXR-treated rats. Furthermore, his- tological examination of the heart sections confirmed the myocardial injury with DXR administra- tion, and the near normal pattern with B. mori, quercetin and benazepril pretreatment. The results provide clear evidence that the B. mori, quercetin and benazepril pretreatments offer significant pro- tection against DXR-induced enzymatic changes in serum, cardiac and renal tissue damage.