Seasonal changes in heavy metals (Cd, Cu, Fe, Pb, Zn) concentrations in muscle tissues of both male and female caramote shrimp (Penaeus kerathurus) from Izmir bay, Turkey were measured for a year period by using flame and graphite furnace AAS. The relationships in various heavy metal concentrations were compared according to sex and seasons. Heavy metal content varied with type of metals, seasons and sex. The highest concentration of heavy metal in the muscle tissue of P. kerathurus for Cd, Pb, Cu, Fe and Zn was registered in Summer months. Mean Fe level in male shrimps was considerably higher (30.19 compared to 20.23 mu g g(-1) dry eight) in October. Regarding Cu, the same case could be observed (27.58 mu g g(-1) dry weight in males compared to 19.02 in females). In the present study, heavy metals accumulated in the shrimp muscle in the order Zn>Fe>Cu>Pb>Cd. Concentrations of metals ranged within the recommended limits for human consumption and not represent a health risk.