13C and1H NMR parameters were measured for dichloroisoproterenol in solution. Spin-lattice relaxation rates, nuclear Overhauser effects and J couplings were determined and compared to those obtained from isoproterenol. The t rotamer was shown to occur with a much higher probability than the two g rotamers. Dynamics in solution were interpreted in terms of a nearly isotropic motion of an extended molecular backbone. Some interesting differences were given evidence between the ‘preferred’ conformations in solution of dichloroisoproterenol and isoproterenol.