Abstract: The investigation was carried out to assess the level of accumulation of heavy metals in the liver of cattle at slaughter during three different seasons: on-set of rainy season (April-July, 2004), peak of rainy season (July-October, 2004) and dry season (January-April, 2005), to identify the season of probable highest accumulation, the most and the least accumulated metals, which might give some clue to any variation in seasonal heavy metal pollution. Pollution is one of the major environmental problems requiring attention globally. As a result of this global problem, contaminations of various sources of food for humans have been reported. Possible markers of environmental pollution have been sought for a proper evaluation of pollutants level and monitoring. Pollutant metals of environmental concern, including lead, cadmium, zinc, cobalt, copper and iron were studied in this investigation. Liver samples were collected from cows at slaughter at Awka abattoir; the samples were digested with phosphoric acid and analyzed for the heavy metals using atomic absorption spectrophotometer, model Shimadzu AA-6800. During the three seasons, Zn was bioaccumulated most (3.00 B 14.40 mg kg-1), followed by Pb (0.09 B 7.32 mg kg-1 and the least being Cd (0.001 B 0.03 mg kg-1). Statistical analysis showed a good correlation between the levels of Pb and Co, Pb and Zn and between Co and Zn, implying that cattle liver accumulations of Pb and Co are functions of Co and/or Zn levels in the liver. It could also be inferred that heavy metal bioaccumulation by cattle is affected by season.