A service failure and its negative effects can involve multiple customers at the same time, which suggests the need to understand the psychological mechanisms that underlie differential perceptions of group service failures (GSFs) versus individual service failures (ISFs) as well as their related outcomes. With an attributional framework, this article reports on two experiments that varied in their blame-attribution ambiguity. The results reveal that customers experience greater anger and show higher negative word-of-mouth and complaint intentions after a GSF versus an ISF. These differential effects are mediated by blame attributions, such that GSFs cause customers to blame the service provider more than ISFs. Customer entitlement also moderates the effect of the failure context (GSF vs. ISF) on blame attribution, contingent on perceptions of whether the service provider or customer violated an existing rule. Thus, we find that customers respond differently to service failures depending on the context. Managerial implications include separating customers from each other when GSFs are likely to take place, using techniques to redirect customer’s blame attributions to sources other than the service provider after a GSF and using customer scripts to minimize the occurrence of customer-induced service failures.