Journal article: The literature on couples’ labour market behaviour is rather scant. We investigate here the determinants of spouses’ labour market activity in France. Our analysis is of exploratory nature. We use data drawn from the French Labour Force surveys of the years 1990-2002. We find that the proportion of dual-earners couples has risen substantially over the period considered. Positive assortative mating is one of the major determinants of joint labour market behaviour of spouses. We also analyze wage inequalities between spouses in dual-earners couples. We find that a non-negligeable proportion of women, roughly one fifth of women in dual-earners couples, earn higher salaries than their husbands. We conclude that the education level, the presence of children and positive assortative mating are the main driving factors for this phenomenon.