Objective: Brucellosis was one of the most important health problems in post-Civil War Spain and in subsequent years. The objective of the study was to reconstruct the first programs that the WHO set up in this country, to address this problem, between 1951 and 1972 and their main outcomes., Methods: On the basis of primary sources of diverse origin, especially unpublished reports on Spain from foreign experts, from the WHO Historical Archive, the contents related to the disease were analyzed, contextualizing them within the framework of both the history of Spanish Public Health during the period studied and the international public health strategies for the prevention and control of brucellosis between 1951 and 1972., Results: Spain 0001 (E1), Spain 0012 (E12) programs were located. The first of them (E1), dedicated to the problem of endemoepidemic diseases (brucellosis, rabies and Q fever), developed between 1952 and 1956, offered assistance in the work of control of these diseases carried out by public health laboratories. The second was preceded by visits of experts between 1956-1958 and formally started in 1969 and ended in 1972. This program was specifically devoted to the fight against brucellosis and included the start-up of laboratory and epidemiological work, the training of specialists, vaccination experiences in goats and sheep and the initiation of studies on immunizations in humans., Conclusions: The presence of consultants and experts from the WHO, from the highest scientific authority in the field of brucellosis such as Sandford Elberg or Martin Kaplan, was decisive in, at least, two aspects: first, to have an external view that would allow to know the reality of the Spanish health situation in the matter of the control of this zoonosis and, secondly, to start up and develop laboratory techniques and training of specialists with the aim of creating, at least, a center of reference for the preparation of vaccines, which the experts placed, ideally, in the National School of Health in Madrid.