Recent service research has paid increasing attention to the effect that emotions displayed by service employees have on customer hedonic well-being. However, fairly little is known about contextual factors determining such emotional contagion. Relying on attribution theory, this research proposes that customers’ attributions for the causes of emotions displayed by employees affect the extent of emotional contagion. Results of an online-experiment (n = 172) in a typical customer service interaction show that attribution effects differ between negative and positive emotional displays of employees. With regard to negative emotional display, emotional contagion is less likely when customers can attribute an employee’s negative affect to uncontrollable causes. In contrast, positive emotional contagion effects are stronger when customers can attribute positive affect of the frontline employee to uncontrollable causes.