This study explores sex differences in perceptions of discovered deception, and the subsequent emotional reactions that are experienced by relational partners. Drawing upon research examining deception, relational communication, and gender, several hypotheses were developed and tested in a sample of 190 respondents who had recently discovered the lie of a friend or romantic partner. The data were consistent with the hypotheses. Women were more likely than men to rate lying as an unacceptable form of behavior within both friendship and romantic relationships. In addition, women rated the act of lying (regardless of what was lied about) as more significant, and reported more negative emotional reactions upon discovering deception than did men. Generalized communicative suspicion functioned to enhance the intensity of emotional reactions for women, but not for men. Implications of the current results for the study of deception are discussed. © 1992, Taylor & Francis Group, LLC. All rights reserved.