Background and Aim: The objective of this study was to determine the contents of heavy metals Hg, Cd and Pb in the muscle, liver and gill tissues of Liza abu fish in the Dez and Bahmanshir Rivers in Khoozestan Province, Iran in winter 2010. 

Materials and Methods: The study included 108 samples of Liza abu tissues. The metals were extracted from the tissues using the wet-digestion method and their concentrations were determined by atomic absorption spectrophotometer Perkin Elmer 4100. Analysis of the data was done using the SPSS17 software, the statistical test being the t-test ((p≤0.05).). 

Results: The highest concentrations (mg/Kg) of Hg (0.029±0.005), Cd (0.506±0.047) and Pb (1.07±0.096) were found in the gill and their lowest concentrations, 0.023±0.001, 0.346±0.040 and 0.903±0.030, respectively, in the muscle. The concentrations of Cd in the gull, muscle and liver were significantly different (p≤0.05) between the Dez and Bahmanshir River fish samples, but the differences with regard to Hg and Pb concentrations were not different between the 2 rivers (p≥0.05). 

Conclusion: The mercury content of Liza abu tissues was lower, while the lead and cadmium contents were higher, than the respective WHO standards (permitted levels).