Computer modeling and simulation techniques are playing an increasingly central role in changing both the way medicine is taught and the way it is practiced. Fundamental to the art and science of modeling and simulation is an underlying assumption that insight into system behavior can be developed or enhanced from a model that adequately represents a selected subset of the system's attributes. Simulation design considerations include: the provision of an appropriate user interface; determining optimal simulation complexity; defining a tutorial strategy; selecting authoring tools; assessing hardware requirements; identifying user needs; defining pedagogical goals; verification and validation; and system evaluation. Significant trends in simulation include the development of improved authoring tools, migration to desktop hardware platforms, and integration of simulation techniques with other types of applications. A further overview of the state-of-the-art of simulation in medicine is given.