ABSTRACT The World Health Organization (WHO) Framework Convention on Tobacco Control has identified the understanding of women and their tobacco-related issues as well as the need for the development of gender-relevant tobacco control efforts as priorities. However, there is a paucity of studies addressing the efficacy of gender-relevant tobacco cessation programs, particularly in low-resource settings (including the U.S.), that take into consideration the limitations and strengths of a health care system. We developed and established the efficacy of a theory-based, culturally- and gender-relevant Community Health Worker (CHW) intervention for low-income Brazilian women that augments the tobacco cessation program offered through the public health system. This application represents the continuation of our gender-relevant tobacco control efforts in Brazil by proposing the adaptation of this CHW-delivered tobacco cessation program to be integrated with mHealth support through mobile devices (App). We are proposing an integrated CHW-mHealth application that (a) is culturally- and gender-relevant, (b) is theory-based (Social Cognitive Theory), (c) considers the existing structure of the Brazilian health care system, and (d) will be adapted based on an efficacious intervention as well as salient features of other mHealth applications that have been shown to be successful in engaging users. During the R21 phase, we will make the adaptations and determine feasibility of a CHW-delivered intervention that is integrated with a mHealth tobacco cessation application (interactive App for participants and tracking system for CHWs) through formative assessments among all involved stakeholders, pretesting, and pilot testing of the intervention. In the R33 phase, we will assess the effectiveness of the integrated CHW-mHealth tobacco cessation intervention through a group randomized trial with towns as the unit of randomization (8 towns, N=344). The comparison group will be the same as the previous intervention (consisting of a home visit by a CHW during which the participant is scheduled to attend the tobacco cessation program at the neighborhood public health clinic) to allow for comparisons. We hypothesize that at 6-months, women smokers who receive the integrated CHW-mHealth intervention will have significantly higher 7-day point prevalence abstinence (defined as no cigarettes in the past 7 days) than women smokers in the control condition. Self-report will be verified through measurement of exhaled carbon monoxide levels among 30% of participants. If shown to be effective, this approach could be utilized as a model for a population-based intervention in low- resource settings, including rural and disadvantaged women in the U.S.