Organochlorine and metal pollution were studied in fish from different sites of the river Seine situated upstream and downstream of Paris. The metal content in roach were similar to those usually found in freshwater fish species. The PCB and the Pb pollutant levels in the fish evolved similarly along the river: from 1300 to 16,000 micrograms/kg dry weight for the PCBs and from 0.3 to 9.5 mg/kg for Pb, while the content of other metals did not change. The stations with the highest organochlorine contents are situated downstream from the Parisian discharges where there is a reduction of fish species present from 31 to 18. Fish caught at one station situated downstream from an industrial area (Guernes) contained a higher proportion of tri- and tetrachlorobiphenyls than fish from the other stations. Their muscle contents are above the French Food Standard of 2 ppm for PCB in fresh muscle.