The objective of this study was to assess the effects of omega-3 fatty acid supplementation on various kidney transplant-related outcomes. A systematic review and meta-analysis was performed of published randomized, controlled trials (RCT). There were 16 kidney transplant RCT with a total of 812 patients. All trials evaluated fish oil with dosages that ranged from 1.2 to 5.4 g/d. No consistent benefits were observed for any outcome with the exception of a modest benefit on triglycerides. A meta-analysis of rejection episodes found no significant benefit on either early (<6 mo posttransplantation) or late episodes. The overall relative risk of having at least one rejection episode in those who received fish oil was 0.91 (95% confidence interval 0.74 to 1.10) in four studies with a follow-up of 1 yr. A meta-analysis of eight RCT of graft survival found no significant benefit (relative risk 1.00, 95% confidence interval 0.96 to 1.05). The available data (mostly derived from older studies with important methodologic limitations) do not demonstrate a consistent, clinically important benefit of fish oil in kidney transplantation.