OBJECTIVE: n-3 Polyunsaturated fatty acids (PUFAs) supplementation reduces systemic inflammation and improves renal and cardiovascular prognosis in kidney transplant recipients. However, patient compliance is poor because bad-tasting fish oils are used as an n-3 PUFA source. Therefore, we explored whether the beneficial effects of n-3 can be obtained by administering a diet based on n-3-rich foods. METHODS: Sixty kidney transplant recipients were assigned to 2 different groups: the CON group (n = 28), which continued with their usual diet, and the DIET group (n = 32), which followed an n-3-rich diet for 6 months. Twenty-six patients in the DIET group and 24 in the CON group completed the study. End points of the study were changes in n-3 PUFAs intake, n-6:n-3 PUFAs ratio, systemic inflammation markers, and renal function during the 6 months of the dietary treatment. RESULTS: Three and 6 months after the beginning of the study, n-3 PUFA intake was significantly higher and the n-6:n-3 PUFA ratio was markedly lower than baseline in the DIET group. Plasma total cholesterol, triglycerides, C-reactive protein, and interleukin (IL)-6 decreased as well. IL-6 mRNA levels in peripheral blood mononuclear cells were also lower than at the beginning of the study. Proteinuria and microalbuminuria were reduced by 50% with respect to the baseline, whereas glomerular filtration rate (GFR) was unchanged. No change in the aforementioned parameters was observed in the CON group throughout the study. CONCLUSION: In long-term kidney transplant recipients a naturally n-3 PUFA-rich dietary plan causes an increase in n-3 PUFA intake, decreases systemic inflammation and proteinuria, and improves plasma lipid pattern.