This paper estimates returns to schooling at Spanish regional level. We identify two different convergence clubs of rich/educated and poor/uneducated regions. Overall our results stress the importance of the relationship existing between the level of development of an economy and returns to different levels of education. In particular, the Spanish evidence suggests that, while primary schooling seems to contribute to growth in poorly developed areas, more skilled human capital has a stronger growth-enhancing effect in more developed economies. In other words, our evidence emphasizes that there is likely to be heterogeneity in rates of returns to education across economies since the effect of schooling in growth regressions is influenced by the level of development of an economy. Failing to take this heterogeneity into account in empirical analysis may produce misleading results