This study of full-time managers and professionals examined whether variables selected from theories of the psychology of gender as well as identity, boundary, and role theories explained effects of sex on work-to-family conflict and “positive spillover.” Women experienced higher positive spillover than men, primarily because they were higher in femininity. Although women did not experience different levels of conflict than men, individuals who scored higher on measured family role salience, which was positively related to femininity, experienced lower levels of conflict. Role segmentation not only reduced conflict but also had the unintended consequence of reducing positive spillover.