[One hundred years of vaccination in Yucatán, Mexico, 1802-1902].

This article analyzes the introduction, spread, and challenges of vaccination in Yucatán, Mexico, from its introduction in 1802 through 1902, a period marked by recurrent vaccination campaigns. Using quantitative and qualitative sources, I approach the arrival of the vaccine and the initial efforts made by authorities to promote it throughout the region. I studied the population's resistance to vaccination and the state's strategies to disseminate the antidote. I also present graphs showing the number of people inoculated, mainly at the end of the nineteenth century. I argue that despite the initial efforts, multiple setbacks hindered the effective development of the vaccination campaigns, but the vaccination became consolidated over time.