Lectin-functionalized monolithic columns were prepared within polyether ether ketone (PEEK) columns (150 × 4.6 mm id) via transition metal-catalyzed ring-opening metathesis polymerization of norborn-2-ene (NBE) and trimethylolpropane-tris(5-norbornene-2-carboxylate) (CL) using the first-generation Grubbs initiator RuCl2(PCy3)2(CHPh) (1, Cy = cyclohexyl) in the presence of a macro- and microporogen, i.e. of 2-propanol and toluene. Postsynthesis functionalization was accomplished via in situ grafting of 2,5-dioxopyrrolidin-1-yl-bicyclo[2.2.1]hept-5-ene-2-carboxylate to the surface of the monoliths followed by reaction with α,ω-diamino-poly(ethyleneglycol). The pore structure of the poly(ethyleneglycol)- derivatized monoliths was investigated by electron microscopy and inverse-size exclusion chromatography, respectively. The amino-poly(ethyleneglycol) functionalized monolithic columns were then successfully used for the immobilization of lectin from Lens culinaris hemagglutinin. The thus prepared lectin-functionalized monoliths were applied to the affinity chromatography-based purification of glucose oxidase. The binding capacity of Lens culinaris hemagglutinin-immobilized monolithic column for glucose oxidase was found to be 2.2 mg/column.