Since age plays an important role in learning a second or foreign language, the present study investigated how different students in different age groups used language learning strategies. The participants of this study were 94 Iranian EFL students from four educational levels and different age groups as, primary (10-12), guidance (13-15), high school (16- 18), and university students (19-23). The Strategy Inventory for Language Learning was used as an instrument in the study. The results revealed that different age groups used different language learning strategies. Running a one-way ANOVA indicated a significant difference between age groups and using language learning strategies. Moreover, the outcomes of this study showed that in comparison with other learning strategies, compensation strategies used more frequently by guidance, high school, and university students. Among different learning strategies, social and affective strategies were used more frequently by university students. Therefore, teachers should consider age group preferences for using language learning strategies and adjust their teaching in a way to meet the students' needs in learning a second or foreign language.