The daughter-guarding hypothesis posits that “parents possess adaptations with design features that function to defend their daughter’s sexual reputation, preserve her mate value, and protect her from sexual victimization” (Perilloux, Fleischman, & Buss, 2008, p. 219). One way that parents may attempt to guard their daughters’ sexualities is by conveying to them certain messages about sex. To explore this possibility we administered an online questionnaire that tested 8 sex-linked predictions derived from the daughter-guarding hypothesis about the content of parent–child communications about sex. Participants were undergraduates from a Northeastern U.S. Jesuit Catholic university (n = 226) and young adults recruited through Facebook (n = 391). As predicted, daughters were more likely than sons to recall receiving messages from their parents that (a) emphasized being discriminating in allocating sexual access; (b) emphasized abstinence; (c) encouraged them to deter, inhibit, and defend against their partners’ sexual advances; (d) encouraged them to not emulate depictions of sexual activity; (e) stipulated when they were old enough to date; and (f) curtailed contact with the opposite sex. Results supported several hypothesized design features of the daughter-guarding hypothesis. Parents may be socializing children in ways that fostered ancestral reproductive success through sex-linked birds-and-the-bees talks and messages.