This study seeks to explore the effectiveness of flipped instruction on the Iranian intermediate English as a Foreign Language (EFL) learners reading comprehension and grammar learning. As the participants of the study, 60 Iranian intermediate EFL learners from a language institute in Kerman, Iran, were recruited based on convenience sampling in the form of two intact classes. Then, to conduct randomization, the two classes were randomly assigned to two groups namely, flipping group and control group. Next, the two groups were exposed to 14 treatment sessions in which reading comprehension and grammar were taught to the flipping group through explicit flipped instruction and to the control group through non-flipped mainstream instruction used in the institute. Data collection tools employed in the study included the Quick Placement Test (QPT), Michigan test of grammar, Michigan test of reading, and SPSS 21 software. The results revealed the significant effectiveness of flipped instruction on the Iranian intermediate EFL learners' reading comprehension and grammar learning. Accordingly, it is suggested that EFL teachers use flipped instruction if they seek to enhance EFL learners' reading comprehension and grammatical knowledge.
