Background: Eicosapentaenoic acid (EPA) from fish is known to have benefits on cardiovascular system by attenuating ischemic changes. Intending to produce alternative source to fish EPA, we have microbially synthesized EPA (mEPA) from α-linolenic acid from plant oil for pharmacological evaluation in myocardial infarction MI. Objective: The objective of present study was to evaluate cardioprotective activity of mEPA through effect on cardiac enzyme biomarkers and histopathology in experimentally induced MI. Methods: Animals were divided into 7 groups of six animals each; control, standard (Losartan 20 mg/kg); fish oil (1 g/ kg); 3 groups with mEPA (5, 10 and 50 mg/kg) for 15 days. MI was induced in all groups except control by two doses of Isoproterenol HCl at 24 hrs interval (50 mg/ 100 g; s. c.) at the end of treatment. Biochemical assays for serum CK-MB, LDH, SGOT, NO, ACE and antioxidant enzymes were performed. Histopathology of ventricular apex region was done to compare pathological changes. Results: Elevated levels of enzymes CK-MB, SGOT, LDH, NO, ACE and reduced levels of antioxidant enzymes in sham control group were significantly reversed in treatment groups. The effects of mEPA were significant as compared to standard and fish oil. This was evident from the histopathological observations of ventricular apex which indicated necrosis and other pathological changes in MI induced group which were decreased in treatment groups. Conclusion: mEPA has shown promising cardioprotective effect and can fulfil the need of alternative source of EPA to fish for use in MI patients.