The rapid growth in the availability of microcomputers, and the vast and growing pool of available medical-demographic data, together underscore the usefulness of software tools which make the analyst's job easier. MEDDAS is one in a aeries of software packages designed to aid in one or more aspects of demographic research. Although the program development was motivated by applications in standard demographic time-series, and in health and disease statistics, the program could prove useful in other applications as well.