© 2016, Springer Science+Business Media Dordrecht.This paper uses the natural experiment of a large imbalance between men and women of marriageable age in Taiwan in the 1960s to test the hypothesis that higher sex ratios lead to husbands (wives) having a lower (higher) share of couple’s time in leisure and higher (lower) share of the couple’s total work time (employment, commuting, and housework). The sample includes 18,134 Taiwanese couples’ time diaries from 1987, 1990, and 1994. The OLS analysis finds evidence of the predicted effects of the county-level sex ratio on husbands’ and wives’ share of leisure and total work time. The county-level sex ratio’s impact on college-educated husbands’ time use is shown to be larger than the impact on non-college-educated husbands’ time use. A two-stage least square analysis controlling for possible endogeneity of county of residence returns similar findings.