Abstarct: In EFL settings, particularly within school environments, most teachers encounter classes with learners exhibiting diverse levels of English proficiency. This heterogeneity presents numerous challenges within English language classrooms. This research aims to identify the key areas where teachers face the most significant challenges and to investigate the extent to which they utilize relevant teaching strategies. Ultimately, the goal is to gain a comprehensive understanding of the challenges faced by EFL teachers in Iran to provide valuable insights to policymakers to address these issues effectively. To this end, a quantitative research method was employed, involving the distribution of a questionnaire to 91 EFL teachers in Iranian secondary schools. The findings revealed that the greatest challenges lie in the areas of teaching and learning, and strategies related to needs analysis require further training and attention.