The family investment hypothesis predicts that credit-constrained immigrant families adopt a household strategy for financing post-migration human capital investment in which the partner with labor market comparative advantage engages in investment activities and the other partner undertakes labor market activities which finance current consumption. We assess this hypothesis by focusing on two issues: first, the extent to which the specialization in the investing versus financing role is based on comparative advantage versus gender, and second, the extent to which credit constraints offer a potential explanation for observed behavior. Using a unique new Australian data set we find that comparative advantage and gender can be separately identified in migrating families. We find some support for the family investment hypothesis among traditional families (where labor market comparative advantage resides with the male partner) but not among nontraditional families.