The elucidation of individual differences in tobacco use motivation is of considerable interest. Accordingly, the present study tested the hypothesis that between-person variation in reinforcement smoking (RS)--a tendency to smoke to regulate affect--moderates the relationship between poor mood and urge to smoke. In this cross-sectional, correlational study, smokers (N = 212; > or =5 cig/day) completed measures of RS, positive affect (PA), negative affect (NA), and smoking urge. RS significantly moderated the relation between PA and urge (betas > .11, ps < .04), such that the inverse correlation between PA and urge was stronger among smokers higher in RS. NA was positively correlated with urge in the overall sample (rs = .34, ps < .0001), but RS did not moderate this relationship. The overall results were consistent across 2 measures of mood and adjusted models that controlled for demographics and smoking characteristics. Continued investigation of these moderational pathways could identify which smokers may benefit most from treatments that target mood during smoking cessation.