In this paper we propose an estimation of capital stock series for the industrial sector of the Mexican states. In order to do it, the average age of the capital stock is calculated by estimating an empirical model that relates investment rates and employment. The empirical findings suggest a significant interregional variation in the capital stock age that coincides with technology differences among industrialized and the not (or less) industrialized states. The regional tendencies of the capital stock series indicate a growing relationship among the capital-labor ratios and a relatively stable investment rate, an advanced result from the economic theory.