This study was aimed to evaluate the preventive role of (-)epigallocatechin-gallate (EGCG) on lysosomal enzymes in isoproterenol (ISO)-induced myocardial infarcted rats. Male albino Wistar rats were pretreated with EGCG (30 mg/kg) daily for a period of 21 days. After the treatment period, ISO (100 mg/kg) was subcutaneously injected to rats at intervals of 24h for 2 days. The activities of lysosomal enzymes (beta-glucuronidase, beta-N-acetylglucosaminidase, beta-galactosidase, cathepsin-B and cathepsin-D) were increased significantly (P<0.05) in serum and the heart of ISO-induced rats. ISO-induction also resulted in decreased stability of membranes, which was reflected by decreased activities of beta-glucuronidase and cathepsin-D in mitochondrial, nuclear, lysosomal and microsomal fractions. Pretreatment with EGCG daily for a period of 21 days to ISO-induced rats prevented the changes in the activities of these enzymes. Oral treatment with EGCG (30 mg/kg) to normal control rats did not show any significant effect in all the biochemical parameters studied. Thus, the results of our study shows that EGCG protects the lysosomal membrane against ISO-induced cardiac damage. The observed effects might be due to the free radical scavenging and membrane stabilizing properties of EGCG.