In this study, Nickel (Ni), Lead (Pb), Cadmium (Cd) and Chromium (Cr) concentrations were determined in muscle, liver, kidney, gills and gonads of Indian mackerel (Rastrelliger kanagurta) collected from Karachi fish Harbour, Karachi coast, Pakistan, during August 2006 and December 2011. Generally, the fish showed the highest level of Ni (2.26 +/- 0.89 mu g g(-1)), Pb (1.45 +/- 0.40 mu g g(-1)), Cd (2.07 +/- 0.75 mu g g(-1)) and Cr (1.52 +/- 0.69 mu g g(-1)) in the liver. The studied metals were the most abundant in the liver than the other organs of the fish. The amount of metal accumulation in fish tissues was evaluated in terms of human health. It was seen that bioaccumulations in muscle tissues of the fish caught from Karachi coast of Pakistan did not exceed the limit values.