This study investigated the effects of collaborative reflection (CR) on Iranian English language teachers' intercultural instructional practice. The data were gathered by observing the classroom instruction of four novice and experienced teachers before and after eight CR sessions. The result revealed that CR was an effective tool for improving teachers' ICC skills and practice as it enabled them to notice cultural episodes of the lessons and teach ICC productively based on the principles and models learned from CR. Nonetheless, although CR was beneficial for all teachers, the novice ones took more advantages from the CR sessions.