We tested whether increased gender-nonconformity (masculinity in women, femininity in men) would increase sociosexuality (SOI) in women, but decrease in men, since SOI is on average higher in men than in women. Czech and Brazilian heterosexual (246) and homosexual (301) men, and heterosexual (475) and homosexual (118) women under 40 years of age reported their childhood-gender-nonconformity (CGN) and SOI.