In this study, solid-phase microextraction fibers coated with modified silica particles (5 pm dp) bonded to methyl (C1), hexyl (C6), octyl (C8), and polymeric octadecyl (C18) groups are prepared and evaluated. Selective extraction of polycyclic aromatic hydrocarbons (PAHs) from river water is used to demonstrate the selective behavior of the fibers as a function of the alkyl chains bonded to the silica phase. Scanning electron micrography suggests that the coating structure consists in a monolayer of particles bonded to the surface of the fiber. The behavior of the fibers upon the extraction of PAHs from water samples is compared with the use of standard polydimethylsiloxane fibers that are commercially available.