A new method to prepare monolayers of omega-alk-1-ene-silane-functionalized Fe3O4 nanoparticles, covalently linked to a hydrogen-terminated silicon (111) surface by thermal hydrosilylation is reported (see Figure). The nanoparticle monolayer on silicon system was structurally and magnetically characterized, and the technique could be extended to fabricate particle layers of other materials that show chemical affinity for the trimethoxysilane group.