This paper exploits unrealized intentions to migrate to highlight mobility constraints. I analyze the discrepancies between Mexicans’ intention to migrate and their subsequent migration behavior using the two waves of the Mexican Family Life Survey panel (2002 and 2005–06). I first provide evidence that intentions contain behavioral information. Controlling for various shocks likely to affect the migration decision, I find that women’s probability to carry out their migration plans is systematically lower than men’s. Different interpretations are investigated, but empirical evidence suggests that women’s unrealized migration plans are due to female-specific costs and constraints.