There is great interest in using computer-assisted instruction in medical education, but getting computer-assisted instruction materials used broadly is difficult to achieve. We describe a successful model for the development and maintenance of a specific type of computer-assisted instruction - virtual patients - in medical education. The collaborative model's seven key components are described and compared to other models of diffusion of innovation and curriculum development. The collaborative development model that began in one medical discipline is now extended to two additional disciplines, through partnerships with their respective clerkship director organizations. We believe that the ability to achieve broad use of virtual patients, and to transition the programs from successfully relying on grant funding to financially self-sustaining, resulted directly from the collaborative development and maintenance process. This process can be used in other learning environments and for the development of other types of computer-assisted instruction programs.