This contribution describes the preparation of nonfouling polypeptide brushes via surface-initiated ring-opening polymerization of oligo(ethylene glycol) modified L-lysine N-carboxyanhydrides. Circular dichroism experiments indicated that these surface-anchored polypeptide chains assume an a-helical conformation, which does not change between pH 4 and 9. Furthermore, nonspecific adsorption of fluorescent labeled bovine serum albumin and fibrinogen on glass slides modified with these brushes was greatly reduced compared to unmodified glass substrates.