The known advantages of solid-phase microextraction as a simple, one-step, rapid and solvent free extraction technique are exploited to study the photodegradation kinetics of polychlorinated biphenyls "on-fibre". The obtained results show the possibilities of this new approach not only to monitor the photolysis pathways of such compounds but to determine the photoproducts produced at different irradiation times and/or wavelengths. Photoproducts of PCB decomposition were less chlorinated biphenyls, among them some coplanar congeners have been found, which is important from a toxicological point of view.