Does universal preschool constitute an effective policy tool to promote the development and integration of children from minority groups? We address this question for the children of the Roma--the largest and most disadvantaged minority group in Europe. To tackle the issue of non-random selection into preschool, we exploit variation in the individual distance to the nearest preschool facility. Non-parametric instrumental variable estimations reveal significant short-term gains in terms of children's literacy. Preschool attendance also increases the prevalence of vaccinations but has no effect on other observed health outcomes. Overall, preschool also does not seem to enhance integration measured by children's language proficiency or social-emotional development, at least not in the short term. (author abstract)