Abstract
Gender and sex as moderator variables of the behaviour sexual and fantasies in young university students. The aim of this work was study the influence of sex and gender variables in the sexual behaviour. Role sexual Inventory (Bem, 1974), sexual behaviour and sexual fantasies questionnaire (Hsu et al., 1994) was administrated to 306 university study. Psychometric and structural properties of scales was analyzed. The results endorse psychometric properties, as reliable and valid, was optimum, in agreement with the literature. After describing procedure and obtained results, the main conclusion is to confirm the relationship between gender( masculine, feminine, androgynous and undifferentiated), sex (male, female), and sexual behaviour, though this relation is lower to it expected. Some limitations and future research are suggested.