It is again my pleasure to introduce a special issue of the Journal o f Medical Sys tems dedicated to coverage of the Medical Information Processing Track at the Hawaii International Conference on System Sciences. The first such special issue was Vol. 3, Nos. 1/2, 1979. This year the Medical Information Processing Track received assistance from the following contributing supporters: Ciba-Geigy Corporation, Electronic Data Systems-Federal, HBO & Company, Hoechst-Roussel, Merk Sharp & Dohme, Plenum Publishing Corporation, and Sperry, Univac. We appreciate and acknowledge their important contribution, which assisted in allowing the meeting to expand. There were two special luncheon addresses: Honorable George E. Brown, Jr., from the United States House of Representatives, gave a talk entitled "A System Approach to Federal Reforms on Health Care," and Dr. Gabor Herman of the State University of New York at Buffalo spoke on "Medical Image Processing." There was also a special invited evening address by Dr. Robert S. Ledly of the National Biomedical Research Foundation entitled "Diagnosis by Computer: Two Decades of Progress." There should be little doubt that the high rate of growth that medical information processing systems have experienced in the last 20 years will continue into the next several decades as well. The following list of sessions at the meeting provides some understanding of just how varied the impact of computers has been in the health care industry: Computer-Based Medical Instrumentation, Environmental Health Effects Technology, Application of Data Models and Data Base Systems within the Medical Environment, Computers and the Handicapped, Laboratory Computer Systems, Automated Pharmaceutical Assistance Systems, Programming Language and Operating System Requirements for Medical Information Processing Systems, The Application of Image Processing to Medicine, Computer-Controlled Experiments in Clinical Investigations and Sports Medicine, Human-Computer Data Interfaces for Medical Professionals, Diagnosis by Computer, The Role of Modeling Methods in Medical Diagnosis, and Limited Application Medical Information Processing Systems. The full proceedings of the meeting 1 consist of over 70 papers in these areas. This meeting was again successful in bringing together the designers, users, and im-