Aim: To compare the impact of recommended intakes of fish and fish oil supplements on the omega‐3 index and selected risk factors in patients with coronary heart disease. Methods: A 12‐week crossover intervention comparing the impact of 1 g/day of long‐chain omega‐3 polyunsaturated fatty acids from fresh salmon or fish oil capsules on the omega‐3 index and cardiovascular risk factors. Eleven patients with coronary heart disease, recruited from St. Vincent's Hospital, Melbourne, participated in the study. Results: A decrease in blood pressure (>5 mmHg; P < 0.05) was observed after the fish but not the fish oil. The change in waist to hip ratio also favoured the fish intervention. Resting heart rate fell by a similar amount on both interventions, and the omega‐3 index increased significantly on both; from 6% to 7–8% (P < 0.01). Blood lipids did not improve on either arm. Conclusions: In Australians with coronary heart disease, 1 g/day of long‐chain omega‐3 polyunsaturated fatty acid from fish or supplements over 12 weeks was effective in increasing the omega‐3 index. Fish intake may have additional cardiovascular benefits beyond the omega‐3 effect as evidenced by the substantial blood pressure reduction following the fish arm warranting examination in a larger study.