The detection of interfacial layers in EPDM samples by NMR imaging is reported. Spin- and gradient-echo techniques were used to differentiate between Voids and inhomogeneities inside the elastomer by characteristic changes of the magnetic susceptibility. Layer-like structures were observed which result from folding of the material during the mixing process. The existence of such interfacial layers may have significance for other analytical methods which probe bulk properties as well as for failure analysis.