Concentrations of 12 metals (As, Be, Cd, Cr, Pb, Mo, Ni, Tl, Th, U, V, Hg) were determined in samples of fish and lobster obtained from various stores and markets in New York State. The seafood samples were chosen based on their popularity as a food source and the potential of the species to contain high levels of mercury based on past research results. A total of 177 fish and lobster samples were initially analyzed using combustion for Hg. The samples were then reanalyzed for several elements using microwave digestion followed by inductively coupled plasma mass spectrometry. The detection limits were as follows: 20 ng/g for Th, U, and Hg; 100 ng/g for Be, Cd, V, and As; and 300 ng/g for Cr, Mo, Tl, Pb, and Ni. Twenty-two samples had mercury concentrations greater than the 1,000 ng/g limit set by the Commission of the European Communities. The highest Cd concentration (511 ng/g) was found in a lobster. This level is greater than the 500 ng/g limit set by the Commission of the European Communities. All levels of As, Cd, Cr, Pb, and Ni were below the U.S. Food and Drug Administration action levels for these metals in crustaceans and shellfish. The highest average mercury level (1,190 ng/g) was found in swordfish. The highest average arsenic level (13,400 ng/g) was found in monkfish. Inductively coupled plasma mass spectrometry with microwave digestion was demonstrated to be a very effective technique for analyzing fish and lobster for Hg and other toxic metals.