Project SummaryCardiovascular disease (CVD) is a major cause of morbidity and mortality in adults living with HIV (ALHIV) andcigarette smoking is the single most important modifiable CVD risk factor in this population. Success rates forexisting smoking cessation interventions are relatively low. Poor sleep is more prevalent among smokers moreprevalent among ALHIV can be caused by smoking cessation attempts predicts relapse to former smokingpatterns and represents a parallel pathway to morbidity including increased cardiovascular disease (CVD)among ALHIV. Thus unhealthy sleep may make smoking cessation more difficult and increase cardiovascularrisk and other poor health conditions in ALHIV. Yet poor sleep is amenable to nonpharmacologic interventionsand a pilot study from our group revealed that a sleep health intervention increased smoking cessation rateswhen added to routine smoking cessation treatment. The mechanisms by which improvements in sleep healthenhance tobacco cessation are unknown but improved cognitive and affective functioning are two candidates.To evaluate the efficacy of our sleep training approach to improve sleep health and increase smoking cessationrates in ALHIV the proposed study will supplement an empirically-supported smoking cessation program (6-session 15-week counseling program with varenicline) with a Sleep Training Approach to Reducing Smoking(STARS) intervention developed for smokers. This intervention uniquely addresses (1) existing sleep difficultiesif any prior to quitting that may be associated with HIV status or nicotine use; (2) inoculation against future sleepdifficulties brought on by quitting and/or varenicline; (3) acute intervention on sleep efficiency and duration asthe participant progresses through the program; and (4) development of healthy sleep habits to carry forwardbeyond the intervention. This approach is based on the gold-standard approach to treating insomnia (CognitiveBehavioral Therapy for Insomnia) but includes a number of novel elements tailored to this population. STARSwill be compared to a General Health (GH) educational control. The study will recruit N=200 ALHIV smokerswho are interested in quitting. They will be randomized to smoking cessation with either STARS (N=100) or GH(N=100). The study will measure the efficacy of STARS versus GH to improve objectively measured healthysleep metrics assess its impact on smoking cessation as well as other metrics of CVD risk and determinewhether cognitive and affective variables mediate the association between sleep health and smoking cessation.Results of these studies will provide practical information as well as mechanistic insight into how sleep healthcan be leveraged to optimize smoking cessation treatment in ALHIV.