RESUMEN
Based on the results of a needs analysis program, already conducted in a parallel study, a need-based teacher professional development program (TPDP) was designed and implemented, which was supported by peer coaching (as a follow-up strategy) and evaluation to address the current needs of Iranian English teachers serving at public junior high schools and to offer suggestions for policy and practice. The effectiveness of the program was evaluated through various data collection methods (i.e. focus group discussions, questionnaires, and semi-structured interviews) taking into account the perspectives of teachers, supervisors, and teacher educators. Besides, the possible effects of the program on students' foreign language achievement were investigated. The results of evaluations indicated that although needs-based peer-coached TPDPs were more likely to consolidate English teachers' knowledge, improve their teaching practices, and promote students' academic achievement, teacher education policy-makers and professional development (PD) designers/providers in Iran still followed more traditional approaches, keeping teachers in isolation and not allowing the exchange of ideas to take place among them. The results provide insights for and offer practical suggestions to education policy-makers and TPDP designers/providers in many developing countries including Iran to avoid future failures and discouraging outcomes due to the provision of improper TPDPs that do not take into account the actual professional needs of the teachers.