This research investigates emotional labor events in libraries. Twenty-three librarians kept work diaries for 5 days recording details of interactions with customers and fellow employees in which the emotions the librarians were feeling were in contrast with the emotional expressions they believe their organization desires. Participants reported 83 events, which were analyzed by type of event, interaction partner, feelings and behaviors that were displayed, outcomes that resulted from the event, and the reflection participants provided on how they and their organization could have handled the situation differently. The findings show that emotional labor exists primarily when interacting with customers, colleagues, and superiors. Librarians performed significantly more surface acting than deep acting in regulating their emotional expressions and reported feeling a wide range of emotions during the events. The findings lead to some suggestions for library managers to consider in order to lessen the negative effects of emotional labor in the workplace.