This paper reports an in-depth case study of a rapid application development (RAD) project. RAD is a recent information systems development method noted for its high levels of user involvement and use of iterative prototyping. The paper develops a model of the core features of RAD gleaned from literature such as that published on the dynamic systems development method (DSDM). We report an ethnographic study of a RAD project and use this case material to contrast the theory with the practice of RAD. We conclude the paper with a consideration of a number of possible revisions to the prescriptions of RAD and also discuss the role of RAD within the broader context of IS development.