The concentrations of heavy metal (Fe, Zn, Cu Mn) were recorded in liver and muscles of (72) specimens of Trichiurus lepturus from the coast of Karachi fish harbour from August 2011 to July 2012. Our results indicated that the concentration of heavy metals was found to be generally higher in liver than muscles of fish. The highest mean concentration of Fe (591 ug/g) were recorded in fish liver and also the highest mean concentration of Fe (42.6 ug/g) were recorded in muscles. The lowest mean concentration of Mn (13.6 ug/g) in were recorded in liver of fish and lowest mean concentration of Mn (0.94 ug/g) were also recorded in muscles. Metal concentration significantly varied in different months of the year