Concentrations of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in the Kucukcekmece Lagoon were determined seasonally in the following species/tissues: whole bodies of two fish (Clupeonella cultriventris and Atherina boyeri) and edible tissues (muscles) of three fish (Carassius gibelio, Scardinius erythrophthalmus and Mugil cephalus) inhabiting brackish waters. Comparisons between the previously published metal concentrations in water and sediment samples taken in the same period from the Lagoon were made with those of fish caught from the Lagoon. The relationship between metal concentrations in all fish species and their length/weight was analyzed. 85% of the measured Pb concentrations exceeded the Turkish Food Codex (TFC) and European Commission (EC) limits, whereas 15% of the measured Cd concentrations exceeded the TFC and EC limits. The levels of Zn determined for all seasons in the muscles of the fish were lower than the levels specified by TFC limit, except for S. erythrophthalmus for winter and autumn. However, none of these concentrations in terms of provisional tolerable weekly intake exceeded maximum and guideline levels for contaminants and toxins in food set by FAO/WHO, and for metals and alloys used as food contact materials set by the Council of Europe (CE).