A large number of studies on both animals and humans have demonstrated that learning is influenced by context or secondary cues that are present when an association is formed. Few studies, however, have examined the functional value of attending to context. We first demonstrated that jumping spiders, Phidippus princeps, could be trained to avoid aposematic, distasteful milkweed bugs, Oncopeltus fasciatus. Spiders readily attacked bugs on first exposure but were significantly less likely to do so after eight trials, although they subsequently attacked and ate crickets. Spiders exposed to nontoxic milkweed bugs reared on sunflower seeds did not show the same decline in attack rate. We next examined the effects of secondary contextual cues on spider learning by training spiders to avoid milkweed bugs in one of two environments. When spiders were tested in an environment different from the one in which they were trained, attack rates increased, and spiders no longer demonstrated retention of the association. Spiders tested in the same environment in which they were trained continued to avoid attacking the bugs. These results have potential consequences for the evolution of both predator and prey and point to the importance of studying context-dependent learning.