Concentrations of eight chlorinated pesticides: namely, gamma HCH, Heptachlor, heptachlore epoxide, aldrin, dieldrin, 4,4-DDE, 4,4-DDD, and 4,4-DDT were studied in some mollusks species Monodonta turbinata, Brachidontes variabilis , Patella caerulea, Trochus erithraeus, Strombus persicus and in sediments taken from five different locations: Assin estuary, Jobar estuary, Banias Thermal Electricity Station, Albasia, and Mirkiya River estuary. Sampling was performed at six different times during the period 2006-2007. Results indicated that Assin estuary contained the highest level of contamination followed by Jobar estuary and Mirkiya estuary where sampled mollusks species contained various concentrations of all of the studied pesticides. At Banias Thermal Electricity Station samples showed contamination with heptachlore and heptachlore epoxide only, whereas the concentration of pesticides at Albasia location, much lower than the other locations.