Objective To investigate the protective effects of ω-3 polyunsaturated fatty acids on severe sepsis patients with myocardial injury.Methods Thirty-one patients with severe sepsis were divided into treatment group (17 cases) and control group (14 cases) by random digits table.All patients received partial enteral nutrition and partial parenteral nutrition with equivalent nitrogen and calorie values for 5 days.The control group was given routine therapy and the treatment group was given routine therapy and ω-3 polyunsaturated fatty acids emulsion.The serum malondialdehyde (MDA),superoxide dismutase (SOD),cardiac troponin Ⅰ(cTnI),N-terminal pro-B urine sodium peptide (NT-proBNP) levels and acute physiology and chronic health evaluation (APACHE) Ⅱ score was compared between two groups before and after treatment.Results There was no difference in indicators before treatment between two groups (P ＞ 0.05).The MDA,cTnI,NT-proBNP and APACHE Ⅱ score in two groups after treatment 5 days was lower than that before treatment 1 day,and the SOD was higher than that before treatment (P ＜ 0.05).The MDA,SOD,cTnI and NT-proBNP after treatment 5 days in treatment group was better than that in control group [(7.50 ±2.06) mmol/L vs.(9.24 ± 1.79) mmol/L,(89.22 ± 16.21) mU/L vs.(76.60 ± 15.13) mU/L,(0.65 ± 0.34)μ g/L vs.(1.03 ± 0.62) μ g/L,(1267.13 ± 279.26) ng/L vs.(1532.47 ± 375.73) ng/L],and there was significant difference between two groups (P ＜ 0.05).The APACHE Ⅱ score was no significant difference between two groups after treatment 5 days.Conclusion ω-3 polyunsaturated fatty acids can reduce the oxidative stress and myocardial injury,decrease cTnI and NT-proBNP levels and improve heart function in the patients with severe sepsis.