The effective implementation of any educational reform is largely dependent on the preparation of teachers. In the case of the National English Program in Basic Education, (NEPBE) implemented in public schools in Mexico in 2009, teacher preparation options have been designed by both public and private higher education institutions in several states of the country. Most options have been based on the needs of teacher trainers and educational administrators, rather than on teachers' needs. This paper presents the partial results of a professional development needs analysis carried out with secondary English language teachers in northeast Mexico. The study examined the teachers' previous professional development experiences; their views on professional development contents and formats; and disposition to engage in inquiry-based professional development. Results indicated that stand-alone and degree courses were the only professional development activities the participants had experienced. Other practices such as mentoring, peer observation, attending conferences, or networking, were unfamiliar to the majority of them. Although most of the teachers considered that training courses had a high impact on teaching, some of them valued the impact of professional development practices that involve autonomy, reflection and collaboration. A high percentage of teachers reported disposition to learn about and engage in classroom research.