PAHs and PCBs were measured in the mussel Perumytilus purpuratus (Lamarck) collected from three different sites along the coast of Valdivia and Valparaiso, South-Central and Central Chile, respectively. Pollution at these sites is considered low with PAHs originating mainly from pyrolytic sources according to the Phenanthrene/Anthracene and Fluoranthene/Pyrene ratios. Temporal variation of PAHs was observed in Valdivia, while site variation was observed along the