Abstract:The authors explore the transformation of common lands in Spain in the second half of the 20th Century, when the nation experienced significant structural and political changes. If the 19th Century was defined by privatisation of common lands, the 20th Century experienced slight growth, but there were differences among the regions. Although the legal definition and classification of common lands is fixed, and was determined by the municipal entity, new formulas (such as the montes vecinales en mano común regulated in 1968) appeared to solve the tension between the state and local control. Ultimately, flexibility was the main characteristic of the regulations which allowed for adapting uses to a diversity of regional circumstances. Along with the productive and environmental regulations, the use of common lands for social purposes through the distribution of plots for cultivation was emphasised. Nevertheless, at the end of the 20th Century Spanish legislation concerning common lands was more focused on earlier norms than on the future.