Boric acid and omega-3 are used as essential elements for both animal and human health. Many researchers have shown these beneficial effects on cardiac and inflammatory markers. This study aims to evaluate cardiac protective effect of boric acid and omega-3 against MI (myocardial infarction), probably due to the suppression of pro-inflammatory cytokines of natriuretic peptides in rats. Fifty male Sprague-Dawley rats were randomly divided into five groups: control, MI, MI+boric acid, MI+omega-3, and MI+boric acid+omega-3. Saline solution (2 ml/day), omega-3 (800 mg/kg/day), and boric acid (100 mg/kg/day)+omega-3 (800 mg/kg/day) were orally administered to the relevant groups throughout the 28 days. To constitute the MI model, the rats were exposed to isoproterenol-HCl (ISO) (200 mg/kg, S.C.) on the 27th and 28th. In the MI group, serum levels of CK-MB, BNP, and TNF-alpha are increased significantly. Also, ST waves and heart rates were higher in the MI than the control. These results demonstrate that biochemical results healed in MI+boric acid, MI+omega-3, and MI+boric acid+omega-3 groups compared MI group. ECG and light microscope results supported the findings as well. The statistical analysis showed that boric acid and/or omega-3 has protective effects on cellular damage in MI.