A novel X‐ray source based on parametric X‐ray radiation (PXR) has been put into practical use at the Laboratory for Electron Beam Research and Application (LEBRA), Nihon University, Japan. The PXR beam has been generated from a Si single crystal irradiated by a 100‐MeV electron beam from a linac at the LEBRA. In this study, phase‐contrast imaging experiments using a diffraction‐enhanced imaging (DEI) method have been carried out by using the parametric X‐rays at an energy of 17.5 keV. The successful images obtained by the DEI method have shown detailed inner structures of soft biological tissues more clearly as compared with those by conventional absorption radiography. Given the significant properties of the LEBRA PXR source, i.e., compact system, large X‐ray beam irradiation field of approximately 80 mm in diameter and quasi‐monochromaticity, the result suggests a possible construction of a compact linac‐driven PXR‐DEI device and application to medical diagnoses. Copyright © 2012 John Wiley & Sons, Ltd.