The miscibility of five chitosan/tertiary amide polymer blend systems was studied. Based on the optical transparency of the blend and the existence of a single glass transition temperature, chitosan was found to be miscible with poly(N-vinyl-2-pyrrolidone), poly(N-methyl-N-vinylacetamide), poly(N-N-dimethylacrylamide), poly(2-methyl-2-oxazoline), and poly(2-ethyl-2-oxazoline). Fourier transform infrared spectroscopy showed the existence of hydrogen-bonding interactions between chitosan and the tertiary amide polymers. (C) 2000 John Wiley & Sons, Inc.