Many chemicals induce cell-specific cytotoxicity. Chemicals like doxorubicin induce oxidative stress leading to cardiotoxicity causing abnormalities in ECG and increase in the biomarkers indicating toxicity. Green tea extract (GTE), Camellia sinensis (Theaceae), is reported to exert antioxidant activity mainly by means of its polyphenolic constituent, catechins. Our study was aimed to find out the effect of GTE (25, 50, 100 mg/kg/day p.o. for 30 days) on doxorubicin-induced (3 mg/kg/week, i.p. for 5 weeks) electrocardiographic and biochemical changes in rat heart. It is observed that GTE administered rats were less susceptible to doxorubicin-induced electrocardiographic changes and changes in biochemical markers like lactate dehydrogenase (LDH), creatine kinase (CK), and glutamic oxaloacetate transaminase (GOT) in serum, and superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH), membrane bound enzymes like Na + K + ATPase, Ca 2+ ATPase, Mg 2+ ATPase and decreased lipid peroxidation (LP) in heart tissue, indicating the protection afforded by GTE administration.