Low-polydispersity poly(vinyl oxazolone) has been prepared using nitroxide-mediated living free radical polymerization. Bulk homopolymerization of 2-vinyl-4,4-dimethyl-5-oxazolone (VDMO) in the presence of the alpha-hydrido alkoxyamine initiator 2 and the corresponding nitroxide 1 proceeds to high conversion with polydispersities of less than 1.10. Accurate molecular weight control and low polydispersities (similar to1.04-1.10) were obtained on statistical copolymerization with styrene. Well-defined reactive statistical copolymers with polydispersities ranging from 1.05 to 1.30 were also prepared by copolymerization of oxazolone-functional monomers with acrylates, acrylamides, and N-vinylamides. Reactive block copolymers were prepared by polymerization of VDMO from poly(n-butyl acrylate) starting blocks as well as by polymerization of styrene from poly(VDMO) starting blocks. New polymers were prepared from VDMO-containing polymers and copolymers by nucleophilic ring-opening of the pendant oxazolone rings with amines.