Normal modes and their dispersion have been obtained for polychloroprene in the trans form using Wilson's G F matrix method as modified by Higg's for an infinite polymeric chain. Urey Bradley force field has been used. Several new assignments, which are missing in earlier work, are reported. The assignments of lower frequency modes have been confirmed using inelastic neutron scattering data. The characteristic features of dispersion curves have been explained. Variation of heat capacity as a function of temperature has been predicted. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 186-195, 2011