While psychological reactance is often invoked to explain the unintended boomerang effects of persuasive health messages, underlying processes that might explain how reactance affects behavior are rarely studied. We investigated whether messages that elicit reactance can bias attention by increasing the perception of information that potentially facilitates adverse behavior. Participants (N = 998) were assigned to one of three experimental conditions: reading an aggressive and emotional text asking them to stop eating meat (appeal condition); reading a neutral text about the nativeness and benefits of eating less meat (information condition); or completing an unrelated word count task (control condition). After assessing their reactance, participants were asked to identify as many words as possible in a word grid in which some words related to meat. Compared to the other conditions, the appeal condition elicited the greatest reactance. Furthermore, omnivore participants in this condition identified significantly more meat-related words when they reported higher levels of reactance. By showing that psychological reactance elicited by forceful health appeals increases attention to information that may facilitate the admonished behaviors, our findings contribute to an improved understanding of effective health communication.