The aim of this paper is the presentation of a new version of the anesthesia documentation software, NarkoData, that has been used in routine clinical work in our department as part of an anesthesia information management system (AIMS) since 1995. The performance of this software is presented along with requirements for future development of such a system. The originally used version, NarkoData 3.0, is an online anesthesia documentation software established by the software company ProLogic GmbH. It was primarily developed as a disk-based system for the MacOS operating system (Apple Computer Inc.). Based on our routine experience with the system, a catalogue of requirements was developed that concentrated on improvement in the sequence of work, administration and data management. In 1996, the concepts developed in our department, in close co-operation with medical personnel and the software company, led to a considerable enlargement of the program functions and the subsequent release of a new version of NarkoData. Since 1997, more than 20 000 anesthesia procedures have been recorded annually with this new version at 115 decentralized work stations at our university hospital.