Although there exists abundant literature about convergence across the Spanish regions, most of the research has been developed by using cross-section regressions or data panel techniques with fixed effects, resulting in biased estimates that may make their conclusions less tenable. In addition, many of these studies do not explicitly account for the effect of the traditional variables determining the steady state. This paper is aimed at overcoming these limitations. The main conclusion that stems from our analysis is that the deep reduction in steady-state disparities across the Spanish regions can be attributed to a large extent to the differences in their population growth rates, which are due mainly to inter-regional migrations.