Intranet-technology is the application of Internet-Tools in local networks. With this technique electronic information systems for large hospitals can be realized very easily. This technology has been in routine use in 'Klinikum Grosshadern' for more than one year on over 50 wards and more than 200 computers. The following clinical application areas are described: drug information, nursing information, electronic literature retrieval systems, multimedia teaching und laboratory information systems.