We prepared a surface-bound ROMP initiator on silicon wafers by self-assembly of a trichlorosilanefunctionalized norbornene derivative. From the growth kinetics of polynorbornene previously reported by our group we selected a time/concentration regime which should result in a still-living polymerization on the surface and a high concentration of active Ru-containing chain ends. Cross-metathesis of the growing polymer with several vinyl-functionalized species (Scheme 1) yielded end-functionalized polymer brushes of 50 nm thickness by ellipsometry. Scheme 1: Growth and end-functionalization of poly-Nb polymer films.