Over the past 15?years, many state governments in Mexico have initiated local programs to introduce English at the primary school level. In 2009, the Mexican Ministry of Education formalized the "Programa Nacional de Inglés en Educación Básica" (PNIEB) as part of the national curriculum, based on the argument that increasing the number of English speakers in Mexico is necessary for the country to be globally competitive and to follow the trend in other developing economies of augmenting English instruction in public education. This paper focuses on the implementation of PNIEB and the state programs that preceded it. The authors document the practices and challenges associated with the program based on data collected from interviews with the main stakeholders involved (students and parents, teachers, school principals, and program coordinators) and from classroom observations. The total data-set consisted of over 200 interviews and classroom observations spread over several years from 2008 to 2012. Several challenges are described, including the development of materials, the role of English in relation to other subject areas, and the training of teachers who often speak English but have uneven formal preparation. The status of the teachers, both as second-class citizens within the schools and the instability and irregularities with their contracts, was identified as the most significant challenge to the successful implementation of the programs.