Conduction of clinical trials may benefit from the reuse of EHR data. The upcoming EHR system eHDSI provides data exchange between European countries and thus represents an attractive data source for multinational trials. In this paper we analyze to what extent eHDSI could provide data relevant for trials with a focus on patient recruitment. Data elements identified in the EHR4CR project to be frequently used in trials were mapped to the HL7 templates of the eHDSI document types using the open source tool ART-DECOR. From the 149 EHR4CR data elements, 44 (30%) could be mapped to eHDSI document components. Despite this moderate coverage, eHDSI could still provide a substantial contribution for recruitment by an automatic pre-filtering process of large groups of potential trial candidates.