Computer-based mobile information processing in hospitals is at a turning point of becoming a substantial and integral part of hospital information systems. Its necessity and potential require a comprehensive systematic approach to support the needs of health care professionals and thus to contribute to high quality patient care and medical research. From the authors' point of view, standardized digital documents could become an appropriate basis for distributed mobile information processing in hospitals. An architecture for the integrated co-operative use of conventional, stationary, and mobile information tools is a major research topic at Heidelberg University. The objective of this paper is to present a departmental prototype design to establish mobile information processing as an integral part of hospital information systems through the use of standardized digital documents.