This presentation attempts a brief overview of progress during the first 50 years after the introduction of knowledge-based systems into clinical medicine. Following a brief review of the first 30 years, the present position is summarised. The main objective of the presentation, however, concerns the future: to summarize needs (perceived and actual) for knowledge-based systems in clinical medicine; to assess the characteristics that users perceive as important for future knowledge-based systems; and to define the work that needs to be carried through in order to attain the goal of effective wide introduction of knowledge-based systems into routine clinical practice.