Implementing a Scalable Smoke-free Home Intervention in Armenia and Georgia - Low- and middle-income countries (LMICs) have high rates of tobacco use and secondhand smoke exposure (SHSe). Two countries particularly impacted by tobacco use and SHSe are Armenia (AM) and Georgia (GE), which represent the 11th and 6th highest smoking rates in men globally (51.5% and 55.5%). Notably, a primary source of SHSe among children and most nonsmoking adults in many LMICs, including AM and GE, is the home. Smoke-free homes (SFHs) can reduce SHSe, promote cessation, and possibly disrupt initiation; however, 61.4% of households in AM and GE allow smoking in the home. Thus, promoting SFHs may be an innovative and relatively untapped strategy for chronic disease prevention in these countries – and in other LMICs with high smoking rates. Research focused on implementing evidence-based interventions (EBIs) offers unique opportunities to address the pressing needs in LMICs and to examine key barriers in the adoption, scale-up, and sustainment of EBIs in low-resource settings. This proposal builds on our teams ongoing collaborations which have established: 1) a strong community-based infrastructure for implementing public health programs using local coalitions in 14 communities, in a prior Fogarty R01; and 2) a theory-based SFHs intervention, designed to be brief and adaptable and shown to be effective, generalizable, scalable, and cost-effective among low-income households in the US. This study will: (1) adapt our SFH intervention to be culturally appropriate for AM and GE, using a community-engaged approach and robust adaptation frameworks and methods, and develop in-country capacity for intervention dissemination (via local coalitions) and delivery (via national quitlines); (2) examine effectiveness of the adapted intervention (vs. control) on SFH adoption (primary outcome) among households in AM and GE, using a type 1 hybrid effectiveness-implementation RCT (n=550 participants), with follow-up assessments at 3 and 6 months; and (3) assess intervention reach, adoption, implementation, and maintenance potential, as well as related contextual influences, using a mixed-methods process evaluation. This work will provide a model for adapting and implementing this EBI for AM and GE, which could be used in other countries and/or for other behavioral targets and EBIs in AM, GE, and elsewhere.