Free fatty acids, as important energy metabolism substrates for the heart, play an important role in various cardiovascular diseases; ω-3 PUFA, as an important branch of free fatty acids, has been confirmed by more and more researches to be closely related to cardiovascular diseases. Heart failure, as a common cardiovascular problem, seriously affects people's quality of life. Studies have shown that ω-3 PUFA plays a significant role in the development of heart failure. In this paper, we try to review the metabolism, pathogenesis and therapeutic significance of ω-3 PUFA in heart failure.