Corporate sponsorship of sports, causes, and the arts has become a mainstream communications tool worldwide. The unique marketing opportunities associated with major events also attract nonsponsoring companies seeking to form associations with the event (ambushing). There are strategies available to brands and events which have been ambushed; however, there is only limited information about the effects of those strategies on attainment of sponsorship objectives. In Experiment 1, university staff and students participated by studying paragraphs linking a sponsor to a novel event. Relative to each sponsor-event pair, they then studied one of three different messages about a competitor. Results find a message which linked the competitor and the event increased competitor recall given the event as a cue and event recall given the competitor as a cue. These effects were moderated if there was information about the competitor not being the sponsor. In Experiment 2 ambushing and counter-ambushing information was presented over 2 days. Both types of messages increased competitor recall given the event as a cue and event recall given the competitor as a cue. In addition, "not sponsor" information was not always used even when it should have been recallable. The results can be explained if participants are using three cues: a specific cue such as a brand name, a contextual cue, and a category cue, such as the concept of an event. Findings suggest to sponsoring firms and event properties that counter-ambushing communications may have the unintended effect of strengthening an ambusher-event relationship in memory. (Contains 4 tables and 2 figures.)