The primary purpose of this study was to examine the relationship between language learning strategy use and foreign language achievement, focusing on differences in gender. A total of 263 English as a foreign language students enrolled in English preparatory class program at Necmettin Erbakan University, School of Foreign Languages participated in the study. This was a descriptive study in relational screening model. The Turkish version of "Strategy Inventory of Language Learning (SILL)", originally developed by Oxford (1990) and adapted into Turkish by Cesur and Fer (2007), was used as the data collection tool. Results from the study indicated that metacognitive strategies were the most frequently used strategies among the participants, while cognitive strategies were the least frequently used. There was no significant difference between the male and female students in terms of language learning strategy use except memory strategies. Also, low but statistically significant positive correlations were observed between foreign language achievement and cognitive (r = 0.23; p = 0.00), compensation (r = 0.16; p = 0.01) and metacognitive strategies (r = 0.15; p = 0.02). The findings reported in the study suggest that high-level strategy use could affect students' achievement in foreign language preparatory classes.