Objective To investigate the immunoregulatory effects of immunonutrient ω-3 polyunsaturated fatty acid (PUFA) and its applications in organ transplantation. Methods Relevant literatures of recent years were reviewed. Results The immunoregulatory effects of ω-3 PUFA can inhibit proliferation and activation of the immunocompetent cells including T cell and B cell, reduce cytokine production, modulate immunologic response, improve graft function, pro-long survival, reduce episodes of rejection, and lessen adverse reactions of immunosuppressor.Conclusion ω-3 PUFA should have wide applications in organ transplantation due to its immunoregulatory effects. However, this research should be further studied.