Neutron reflectivity has been used to study the organization ofself-assembled multilayers of sulfonatedpolyaniline and polyallylamine. Films were prepared by thesequential adsorption of polycations andpolyanions from dilute aqueous solutions. Scattering contrast wasachieved by selective deuteration ofthe blocks of bilayers at varying intervals along the film. Themultilayer structure was found to be preservedover 40 bilayer depositions, but with an internal organization whichdecays monotonically away from thesubstrate. These results suggest that the observed interfacialwidths are primarily due to the accumulationof defects as the bilayers are deposited.