The objective of the research presented in this article is to examine the possibility that the adverse effects on consumer brand attitudes engendered by the involvement of a celebrity endorser in a negative event may spill over brands of the same product category (i.e., competitors). The results of an experimental study with 165 adult consumers showed that a scandal involving an athlete endorser had a negative impact not only on the attitude toward the endorsed brand, but also on the attitude toward competitor brands. This suggests that brands strongly associated with one sport may be vulnerable in the context of a scandal falling upon a celebrity athlete endorsing one of their direct competitors.