Öz Although there is an ever increasing interest in the issue of teacher belief systems in mainstream education studies, the beliefs of EFL teachers, especially Iranian teachers‟, about grammar and the influence of such beliefs on their instruction remain relatively unexplored. The present study seeks to examine high school teachers‟ belief regarding teaching grammar. To do so a grammar belief questionnaire and an interview were administered. The result showed that although teachers were compelled by the curriculum and students needs to teach grammar explicitly through present, practice, produce (P.P.P) approach they were well aware of some tenets of focus on form instruction of grammar and valued learning grammar in communicative meaningful activities.