The degree of the biocompatibility of polymeric materials used as biomaterial can be controlled by surface modification for various biomedical engineering applications. This paper reports UV laser-assisted modification of polyethersulfone membrane with respect to the fabrication of polymer devices for cell culture applications. For this purpose physicochemical changes on the membrane surface were investigated as a function of laser and process parameters. The membrane was irradiated with nanosecond UV pulses at 193 and 308 nm. The change in surface chemistry was characterized by FTIR spectroscopy and contact angle measurements. In order to test the influence of these changes for biological applications, the modified membranes were studied for L929 cell culture assay and platelet adhesion.