This article gives an account of a project aimed at improving the teaching practice and self-reflection of English as a foreign language teachers in Manizales (Colombia) by means of a professional development program. At the initial stage, surveys, class observations, and documentary analysis allowed the researchers to identify teachers' professional needs, as well as the areas that needed improvement. During the action stage, class observations, informal chats, and a survey were used in order to reveal the impact of the professional development program. Findings demonstrated that although the program initiated some slight changes in teachers' performance and reflection, it still left space for more training and improvement.