Medical expert systems have been developed for more than 20 years, in particular in the United States. Most existing systems are prototypes, and only a few commercial systems are available. The prototypes are generally limited in scope or functions (and have not been transferred to other users). However, in the near future we can expect useful applications to appear in special areas of medicine. In Norway we probably do not have the resources required to develop large commercial medical expert systems. If we want to develop medical expert systems, we should concentrate on limited areas. We must prepare the ground for future use of such systems in Norway. An important first step is to give health personnel basic education in the use of computers.