OBJECTIVES •Identification of the main contamination pathways of river flow in the French West Indies by chlordecone (CLD) according to different hydrological situations •Estimation of the contributions of dissolved and particulate transport of CLD a molecule highly persistent with high sorption properties HIGHLIGHTS •CLD was applied in banana plantations from 1972 to 1993 and has led to permanent pollution of soils and rivers in the banana cropping areas. •A large water sampling scheme over a wide range of flow rates was conducted at the outlet of a 12,8 km² catchment where soils are highly contaminated •The variation of CLD concentrations proved to be highly non linear with large values for base flow and intense floods as related, for the former, to severe groundwater contamination due to soil leaching and, for the latter, to surface washoff. •Estimation of CLD export on an annual scale shows a major contribution of the dissolved phase (98%) whereas contribution of the particulate phase is similar to the dissolved phase only for flood events.