One of the subjects that has focused the empirical work of many educational economists has been the public funding of privately run schools. In this paper we use a quasiexperimental approach in order to evaluate the effect of attending a Spanish publicly subsidised private school on some of the educational skills promoted by Spanish primary schools. Our results underline the existence of a certain advantage of the publicly subsidised private school in some educational competencies, in particular those related to the dominance of abilities in solving problems and questions related to scientific skills.