The mesquite (Prosopis juliflora (Sw) DC) was established as a successful action of xerophilous introduction in Brazilian Northeast dry region. Its fruits are used in animal feed and the wood may be used as piles, firewood and charcoal. The species was introduced in 1942, spreading in "low areas" in Rio Grande do Norte, Paraiba, Pernambuco, Bahia and Piauí States. This article aims to elucidate how mesquite was introduced in Rio Grande do Norte State and to understand how it was spread. It was first introduced in Rio Grande do Norte State by the introduction experiments installed at São Miguel farm in the municipality of Angicos. The enthusiasm of technicians and researchers promoted the distribution of pods and seedlings on farms and cities in the state. In addition, there were government incentives to production, distribution and planting the species. This work aims to establish considerations to be used as historical basis on studies about this species and to consider aspects regarding current situation of this culture in Brazilian Northeast.