Applying multi-professional electronic health records (EHRs) is expected to improve the quality of patient care and patient safety. Both EHR systems and system users depend on semantic interoperability to function efficiently. A shared clinical terminology comprising unambiguous terms is required for semantic interoperability. Empirical studies of clinical terminology; such as pre-defined headings; in EHR systems are scarce and limited to one profession or one clinical specialty. The aim was to study pre-defined headings applied by users in a Swedish multi-professional EHR system.