Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) concentrations were measured in seabirds from Rio de Janeiro, Brazil. Species, Great Egret and Manx Shearwater, were collected in 2008-2010 on Ilha Grande bay. Detectable hepatic concentrations of PCDD/Fs and PCBs were found in all samples analyzed. The concentrations were below the range of concern established by WHO. This is the first measurements of PCDD/Fs and PCBs congeners in seabirds from this area, and suggests that future studies should take note of the results in order to test for a greater range of compoundsand species and to determine levels of environmental contamination.