This study attempts to investigate the ways in which some language learners make conscious efforts to learn English grammar more efficiently, which strategies they use in language learning, whether a particular learning strategies favors certain strategies or not, if it does, what those strategies are and relationships between strategy use and learner achievement in grammar learning. The use of grammar learning strategies of the students in prep school at the University of Gaziantep was investigated in this study. The relationship between students’ choice of learning strategies in grammar and foreign language achievement was investigated. To sum up, do the use of grammar learning strategies have a positive effect on the student achievement? By knowing this, we can help the students and improve their learning habits.