BACKGROUND: Perceptions regarding the availability of smoking opportunities are known to affect cigarette craving; however, whether they impact actual smoking or how smokers respond to acute nicotine replacement therapy (NRT) administration is not known. This study examined the impact of pharmacological and expectancy components of NRT administration on craving and smoking in smokers anticipating or not anticipating an imminent smoking opportunity. METHODS: In total, 154 smokers (84 male) completed an experimental session in which instructions regarding the nicotine content of a lozenge (4 mg vs. no nicotine) and regarding the availability of a future smoking opportunity were manipulated. Cigarette craving was assessed before and after manipulations and lozenge administration. All participants were then allotted 1h to self-administer as many cigarette puffs as they wished. RESULTS: Unanticipated smoking opportunities reduced latency to self-administration (p<0.001), regardless of nicotine expectancy or pharmacology. When analyses included all participants, nicotine reduced intentions to smoke (p=0.016) and withdrawal-related craving (p=0.043) regardless of expectancy. Conversely, analyses using only "believers" of the nicotine content instructions revealed that nicotine expectancy reduced intentions to smoke (p=0.034) and withdrawal-related craving (p=0.047) regardless of actual nicotine administration. "Believers" also reported increased withdrawal-related craving when a smoking opportunity was perceived to be imminent (p=0.041). These effects were not significant when analyses included all participants. CONCLUSIONS: Findings suggest that unexpected smoking opportunities may be more appealing than expected ones regardless of perceived or actual acute NRT use. They also highlight the importance of reporting balanced placebo findings using all participants as well as "believers" only.