Poly(ethylene terephthalate) (PET) was photografted in a solvent free vapor of maleic anhydride and benzophenone. After hydrolysis of the initially grafted succinic anhydride groups, the carboxylic PET surfaces were modified by coupling reactions in organic and aqueous solutions. 2,2,2-Trifluoroethylan-fine and diamino PEGs of molecular weight 3400 and 2000 were reacted with acid chloride groups obtained by treating the PET-COOH surface with PCl5. Furthermore, fluoro substituted thiols and a cystein terminated RGD containing peptide were bound to PET-COOH surfaces via a disulfide link by a three step coupling sequence. Coupling yields and surface concentrations of the fluoro substituted ligands were calculated from ESCA data. The RGD-peptide surfaces were evaluated by cultivation with rat smooth muscle cells.