Organochlorine pesticides (OCPs) in sediment, water and biota samples from the coastal marine environment of Mumbai were analysed to elucidate their distribution in various environmental compartments.HCH somers,dichlorodiphenyltrichloroethane DDT) and its metabolites were the redominantly identified compounds in all the samples. High ratios of DDT to dichlorodiphenyldichloroethylene (DDE) were found in seawater samples.This indicates the presence of a significant source of DDT in this region. In sediment samples, the γ-isomer contributed almost 55% to the total HCH, indicating a high affinity of the γ-isomer towards the sediment. The levels of organochlorines in fish obtained from this region were found to be lower than the levels of organochlorines in fish in temperate regions.