C-reactive protein (CRP), a strong independent risk marker of cardiovascular disease (CVD), and tumor necrosis factor-alfa (TNF-α), a known pro-inflammatory cytokine, are elevated and have damaging effects in patients with chronic renal failure (CRF). Omega-3 fatty acids play an important modulatory role in inflammatory responses. The aim of this study is to review the alterations in serum levels of TNF-α, CRP and other parameters caused by omega-3 supplementation in dialysis patients. The clinical trial was performed in 37 patients with end-stage renal disease undergoing dialysis in hemodialysis centers of three university hospitals in Tabriz. Blood samples were obtained from the study patients for hemoglobin, albumin, ferritin, triglyceride, total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL)-cholesterol, TNF-α and high specific-CRP (hs-CRP) measurement. The patients received 3 g omega-3 per day for 2 months. The side-effects noticed were nausea, diarrhea and dyspepsia and undesired drug smell. The difference noted in hemoglobin, albumin, ferritin, CRP, triglyceride, total, LDL and HDL-cholesterol before and after supplementation with omega-3 fatty acid was not statistically significant (P > 0.05). However, the use of omega-3 decreased the serum levels of TNF-α significantly. We conclude that the use of 3 g of omega-3 per day caused significant decrease in serum levels of TNF-α in the dialysis population, and its use is recommended in such patients.