The main challenge of this research was to functionalize the surface of poly(L-lactide-co-glycolide) (PLGA) membranes with amphiphilic poly(2-oxazoline) (POx) in order to change PLGA chemical state and properties. Poly(2-oxazolines) are very powerful polymers, which thanks to active pendant groups can be easily functionalized with biologically active molecules or peptides. The membranes were prepared by dissolving PLGA, POx, and poly(ethylene glycol) (PEG, 1000 Da) in methylene chloride (DCM), followed by PEG leaching. POx molecules were preferentially adsorbed at the interface PLGA-POx-PEG thanks to affinity to both hydrophilic (PEG) and hydrophobic (PLGA) chains. The properties of the membranes were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and wettability tests. Cytocompatibility of the materials in contact with osteoblast-like MG-63 cells was studied by evaluation of cell viability (Alamar-Blue test), live/dead and phalloidin/DAPI staining. The results show that the presence of POx influenced topography of the PLGA membranes, but did not have an impact on their wettability. All membranes were fo-und cytocompatible with model osteoblasts. Presence of POx resulted in better cell adhesion as shown by microscopic studies after fluorescence staining for nuclei and cytoskeleton actin filaments. In summary, one-step phase separation process between PLGA, PEG, and POx, dissolved in DCM followed by drying and PEG leaching resulted in cytocompatible PLGA membranes with immobilised POx, which might be considered for guided tissue regeneration technique in periodontology and in bone tissue engineering.