We investigated the effects of antiforeigner political advertisements on implicit and explicit stereotypes. While stereotypical associations may become automatically activated (implicit stereotypes), individuals can reject these thoughts and decide not to use them for an overtly expressed judgment (explicit stereotypes). We hypothesized that even if citizens negated stereotypical content, advertisements might still affect implicit stereotypes. This hypothesis was tested using an experiment where participants (N = 186) were exposed to zero, two, four, or six stereotypical advertisements. The results showed that stereotypical advertisements did not influence explicit stereotypes but did influence implicit stereotypes, even in critical recipients who negated the stereotypical content.