The synthesis and characterization of a bifunctional material containing antimicrobial and antibiofouling components is presented. An end-functionalized antibiofouling poly(oxonorbornene)-based poly(zwitterion) was synthesized and grafted onto a surface-immobilized network of an antimicrobial poly(oxonorbornene), which is in this case a cationic synthetic mimic of an antimicrobial peptide (SMAMP). The resulting material was characterized by Fourier-transform infrared spectroscopy, ellipsometry, atomic force microscopy and surface plasmon resonance spectroscopy (SPR). The SPR data indicate that this bifunctional material is antibiofouling in spite of the underlying cationic SMAMP carpet, and as such it might be a promising material with potentially two lines of defense against biofilm formation.