This article reviews studies of computer and Internet-based interventions for smoking behavior, published between 1995 and August 2004. Following electronic and manual searches of the literature, 19 studies were identified that used automated systems for smoking prevention or cessation, and measured outcomes related to smoking behavior. Studies varied widely in methodology, intervention delivery, participant characteristics, follow-up period, and measurement of cessation. Of eligible studies, nine (47%) reported statistically significant or improved outcomes at the longest follow-up, relative to a comparison group. Few patterns emerged in terms of subject, design or intervention characteristics that led to positive outcomes. The "first generation" format, where participants were mailed computer-generated feedback reports, was the modal intervention format and the one most consistently associated with improved outcomes. Future studies will need to identify whether certain patients are more likely to benefit from such interventions, and which pharmacological and behavioral adjuncts can best promote cessation.