The purpose of the present study was to examine the effect of teaching grammar explicitly on Iranian tourism and hotel management students’ grammar knowledge. The 65 Iranian tourism and hotel management students who participated in this study were homogenized based on the Nelson proficiency test, so 51 tourism and hotel management students were selected as the main participants. They were divided into three experimental groups, which were called the "integrated FFI group," "pre-task FFI group," and "post-task FFI group." The learners' scores were compared using ANCOVA to analyze the data. The learners were pretested using the error correction test to assess their explicit grammar knowledge. After the treatment sessions, learners were post-tested using the error correction test to check the efficacy of the timing of form-focused instruction on the development of explicit knowledge of grammar. Based on the obtained results, it was found that there is a significant difference between the effects of integrated FFI, pre-task FFI, and post-task FFI on the explicit knowledge of the grammar of tourism and hotel management students. Manuscript profile