<p>Individuals with pain who smoke tobacco cigarettes experience increased difficulties in quitting. Research has shown that both pain and smoking behavior may contribute to sleep difficulties, and that sleep difficulties are a known risk factor in the maintenance of smoking. However, there is limited research examining the interrelations between pain, sleep, and smoking cessation-related outcomes among persons who smoke with current pain. The purpose of the present cross-sectional study was to investigate the indirect effect of sleep difficulties on the association between pain intensity and maladaptive cognitive processes implicated in the smoking cessation continuum, including severity of problems when trying to quit, perceived barriers for cessation, and negative mood expectancies related to smoking abstinence. Participants included 90 adults (33.3% female; <i>M</i>_<i>age</i> = 45.3 years, <i>SD</i> = 10.91 years) who experienced pain in the past 6 months and smoked at least one cigarette per day for the past year. Results indicated that sleep difficulties partially explained the relationship between pain intensity and severity of problems when trying to quit (<i>ab</i> = 0.02, <i>SE</i> = 0.01, 95% <i>CI</i> [0.01, 0.03]) and fully explained the relationship between pain intensity and perceived barriers for cessation (<i>ab</i> = 0.14, <i>SE</i> = 0.07, 95% <i>CI</i> [0.02, 0.29]) and negative mood expectancies (<i>ab</i> = 0.15, <i>SE</i> = 0.08, 95% <i>CI</i> [0.02, 0.33]). The present study provides initial evidence that sleep difficulties may serve as an important explanatory factor in associations between pain intensity and smoking cessation processes.</p>