Modification of material surfaces aimed at bestowing them with antimicrobial properties is a promising approach in the development of new biomaterials. Antimicrobial peptides (AMPs) are an attractive alternative to conventional antibiotics because of lack of toxicity, inherently high selectivity, and absence of immune response. As the antimicrobial mode of action of the AMP cathelin LL37 is formation of pores and disruption of microbial membrane, the purpose of the present study was to develop and test a method of covalent immobilization of LL37 on titanium surface. The application of a flexible hydrophilic poly(ethylene glycol) spacer and selective N-terminal conjugation of LL37 resulted in a surface peptide layer which was capable of killing bacteria on contact.