Abstract The levels of dissolved and particle-associated n-alkanes, alkylbenzenes, phthalates, PAHs, anionic surfactants and surfactant fluorescent organic matter (SFOM) were measured in sea-surface microlayer (SML) and sub-surface water (SSL) samples collected in the Leghorn marine environment in September and October 1999. Nine stations, located in the Leghorn harbour and at increasing distances from the Port, were sampled three times on the same day. At all the stations, SML concentrations of the selected organic compounds were significantly higher than SSL values and the enrichment factors (EF=SML concentration/SSL concentration) were greater in the particulate phase than in the dissolved phase. SML concentrations varied greatly among the sampling sites, the highest levels ( n-alkanes 3674 μg/l, phthalates 177 μg/l, total PAHs 226 μg/l) being found in the particulate phase in the Leghorn harbour. To improve the knowledge on pollutant exchanges between sea-surface waters and atmosphere, the validity of spray drop adsorption model (SDAM) was verified for SFOM, surface-active agents, such as phthalates, and compounds which can interact with SFOM, such as n-alkanes and PAHs.