In this diary study, we tested the possibility that dispositional reward and punishment sensitivity, two central constructs of reinforcement sensitivity theory, would modify the relationship between emotional labor and job-related well-being (i.e., work engagement, emotional exhaustion, depersonalization). Specifically, based on a social functional account of emotion, we hypothesized that surface acting entails the risk of social disapproval and therefore may be more detrimental for high than for low punishment-sensitive individuals. In contrast, deep acting is hypothesized to hold the promise of social approval and therefore may be more beneficial for high than for low reward-sensitive individuals. Hypotheses were tested in a sample of 237 service workers (N = 1,584 daily reports) who completed a general survey and daily surveys over the course of 10 working days. Multilevel analyses showed that surface acting was detrimental to well-being, and more strongly so for high than for low punishment-sensitive individuals. The results are consistent with the idea that heightened sensitivity to social disapproval aggravates the negative effects of surface acting.