This paper is focused on the relations between the spatial patterns of territorial and demographic vulnerabilities in Spain. To aim this goal, the study is based on a GIS model of fuzzy logic and multicriteria evaluation, which highlights the spatial gradation of vulnerabilities. The article shows a strategic geodemographic approach, which is addressed at the importance of studying the population, because of the transcendence and implications of the changes experienced by the demo-spatial component at any scale. Furthermore, the study aims a research contribution in the concern that exists in Spain related to the sustainability of certain territories. On the other hand, the article proposes a methodological alternative to analyze the issue of territorial imbalances based not only on the population, but also on the geographical area.