Abstract: Heavy metals such as nickel, copper, zinc and lead, generally are toxic substances that pose a great risk to living organisms in our environment due to their inevitable existence. The aim of this investigation is to investigate and assay the presence of such metals in muscle tissues of tilapia zilli of Gwale Pond in Gwale Local Government Area of Kano State, Nigeria. Muscle tissues of some fresh tilapia zilli were dissected, prepared and assayed by Alpha A4 atomic absorption spectrophotometer. The ranges of working standard concentrations were 0.001 ppm to 1 ppm .Study findings showed that the mean concentrations of nickel, copper, zinc and lead were 0.0120+0.002 ppm, 0.0637+ 0.0035 ppm, 0.0097+0.0006 ppm and 0.0075+0.0005 ppm Respectively. The 95% confidence intervals for nickel, copper, zinc and lead were calculated to be 0.0120 + 0.005, 0.0035 +0.009, 0.0006 +0.001 and 0.0005 +0.001 respectively. The method was validated using triplicate analysis, recovery experiment and statistical analysis