The main objective of this research program lies in explaining the importance of immigrants, visionaries and intermediaries in the expansion of patents and technological change in Mexico, during the last two decades of the Porfiriato (1890-1911). In other words, the intention is to disclose the economic, social and cultural importance of the projects of immigrant inventors who registered their creations in the Mexican Patent System, the local inventors who visionarily patented out of the country and the intermediary agents who facilitated these actions of exchange and circulation of technological knowledge.