Muscular mercury and selenium were assessed in a voracious fish from three Brazilian coastal areas with different environmental conditions. Mercury was higher in specimens from Ilha Grande Bay (0.35 ± 0.17 μg g(-1)) than in cutlassfish from Guanabara Bay (0.30 ± 0.15 μg g(-1)) and Buzios coast (0.13 ± 0.08 μg g(-1)), respectively. No difference was found regarding selenium among these areas. Mercury was positively correlated with fish length and size intervals (sub-adult, small and large adult), suggesting that larger and older fish bioaccumulated more mercury. A large excess of molar selenium in relation to mercury was observed.