The prenatal risks of tobacco smoking motivate many women to quit smoking during pregnancy and to maintain abstinence for several months. Unfortunately, the majority of these women relapse to smoking either during their pregnancy or within the first six months postpartum. Resumption of smoking is associated with cancer and other health risks to the smokers themselves and to those exposed to their environmental tobacco smoke, including the infant and other members of the family. Because so many women are able to achieve at least short-term abstinence during their pregnancy, the pregnancy and postpartum periods are collectively viewed as a "window of opportunity for interventions designed to prevent smoking relapse. Although modest success has been achieved at aiding women in smoking cessation during pregnancy, attempts to prevent subsequent smoking relapse have been unsuccessful to date. The goal of Study I is to develop the key materials for a cost-effective minimal intervention preventing smoking relapse among pregnant/postpartum women. The intervention will be modeled after one developed by the research team that has been found to reduce smoking relapse by approximately two-thirds among a general population of recent quitters. This intervention comprises a series of eight Stay Quit booklets mailed to former smokers over a year. The booklets were developed based on theory and research on smoking relapse, and were found to be extremely cost-effective. However, because pregnant and postpartum women differ in many ways from the general population of ex-smokers, it cannot be assumed that the existing intervention would adequately meet their unique needs. The end product of Study I will be a series often Forever Free for Baby and Me booklets designed to be provided to women between their sixth month of pregnancy and eight months postpartum. The content of the booklets will be based on three sources of information: (1) the existing, validated Stay Quit booklets, (2) theory and research on smoking relapse during and after pregnancy, and (3) systematic formative research comprising focus groups, in-depth interviews, and learner verification interviews. Subjects will include pregnant and postparatum women who have maintained tobacco abstinence, as well as those who have relapsed; their partners; and relevant health professionals in the community. Study II will be a randomized, controlled trial of the intervention developed in Study I. Women who have quit smoking during pregnancy will be recruited via childbirth education classes and randomly assigned to receive the series of Forever Free booklets versus a usual care control condition. Follow up will be conducted through 12 months postpartum, and a format cost-effectiveness analysis wilt be conducted. If shown to be effective, this minimal intervention would be easy and inexpensive to disseminate to women via a variety of channels and settings.