Purpose: After World War II, an educational modernization process gained ground worldwide. International organizations such as UNESCO began to play a key role in the creation, development and dissemination of a new educational vision in different countries. This article examines the origin and development of this modernization process under the dictatorship of Franco. More specifically, we will show how the adoption of this conception in Spain must be understood from the perspective of the interaction between UNESCO and Franco's regime, and how the policies of the dictatorship converged with the proposals suggested by this international organization. Our principal argument is that the educational policies carried out in Spain throughout the second half of the 20th century can be better understood when inserted into a transnational perspective in education. Design/methodology/approach: This article uses documents from archives that until now were unpublished or scarcely known. We have also analyzed materials published in the preeminent educational journals of the dictatorship, such as the "Revista de Educación," "Revista Española de Pedagogía," "Bordón" and "Vida escolar," as well as documents published by the Spanish Ministry of National Education. Findings: Franco's dictatorship built an educational narrative closely aligned with proposals put forward by UNESCO on educational planning after World War II. The educational policies created by the dictatorship were related to the new ideas that strove to link the educational system with economic and social development. Originality/value: This article is inspired by a transnational history of education perspective. On the one hand, it traces the origins of educational modernization under Franco's regime, which represented a technocratic vision of education that is best understood as a result of the impact that international organizations had in the second half of the 20th century. On the other hand, it follows the intensifying relationship between the dictatorship and the educational ideas launched by UNESCO. Both aspects are little known and studied in Spain.