Language can be viewed as sexual displays from an evolutionary perspective. As both sexes in humans contribute significantly to parental care, we can expect that both males and females use language to display their favourable qualities in order to attract potential mates. In this study, 50 participants (22 male, 28 female) rated 30 vignettes, in which a male or female protagonist attempted to impress an opposite sex friend in a conversation. In both male-female and female-male flirtations, conversations revealing the speaker’s positive character traits were the most highly rated while those explicitly showing the speaker’s sexual interest in the potential partner were the most poorly rated. Despite the similarities, there were significant sex differences in the ratings of some individual vignettes and item-groups. Such differences would be chiefly discussed from an evolutionary perspective.