The concentrations of organochlorine pesticides (OCPs) such as hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDT) and its metabolite (DDE) and endosulfans were determined in air and water in order to estimate the magnitude and direction of gas flux across the air–water interface at the creek adjoining Mumbai harbour, India. The range of HCH residues in air was found to be between 1.0 and 22.5 pg m⁻³ and that in sea-water was between 1.7 to 34.4 ng l⁻¹. DDT and its metabolite (DDE) residues in air ranged between 2.1 and 80.8 pg m⁻³ and in sea-water between 1.4 to 19.2 ng l⁻¹. The concentrations of β-endosulfan in air and sea-water samples were found to be 1.0–1.6 pg m⁻³ and 1.0–2.6 ng l⁻¹ respectively. The HCHs revealed positive values of the fluxes (1.001 µg m⁻² d⁻¹ for α-HCH, 0.107 µg m⁻² d⁻¹ for β-HCH and 0.455 µg m⁻² d⁻¹ for γ-HCH) indicating the tendency to transfer these contaminants from water to air. This implies that the marine water bodies principally act as a source of HCHs. The fluxes for DDTs (p,p′-DDE and p,p′-DDT) also follow the same pattern as HCHs and show high positive values (1.698 µg m⁻² d⁻¹ for DDE and 2.422 µg m⁻² d⁻¹ for DDT). The present study suggests the active transfer of these dissolved OCPs into the atmosphere due to volatilization.