Advances in portable equipment have led to routine spirometry testing outside of formal pulmonary function laboratories. Practitioners ordering these tests are not formally trained in spirometry interpretation. Providing effective off-site training can be challenging. Our objective was to develop a remotely accessible computer-based tutorial for teaching spirometry interpretation to nonpulmonologists. We designed an educational module that was accessible via the Internet and tested by 65 medical trainees at a major university medical center. In addition, the module was posted within the Virtual Hospital on the World Wide Web. Increases in spirometry interpretative skills were assessed using pre- and post-tests submitted electronically. The spirometry module significantly improved spirometry interpretation by nonspecialist trainees. This improvement included a broad increase in knowledge base and was observed independent of training level and prior spirometry reading experience. We conclude that computer-based tutorials can effectively train off-site practitioners in spirometry interpretation. This technology allows for the dissemination of educational material from a central site of expertise and provides a valuable adjunct to limited teaching resources.