This article addresses the issue of information availability for decision-making at the subregional level. It proposes the construction of a territorial development index (TDI) based on administrative records and comprising 19 variables grouped into 6 dimensions: (i) cultural capital, (ii) social capital, (iii) human capital, (iv) institutional capital, (v) tangible capital and (vi) economic capital. The approach underlying the proposed model centres on territorial development and the structural factors determining it. The variables making up the TDI were selected in consultation with experts and with the use of multivariate statistical analyses. This paper sets out to document many of the phases, procedures and decisions leading to the TDI, as a way of opening up the discussion around this line of research. It concludes by presenting calculations of the TDI for the Chilean municipalities of Angol and Carahue.