This study investigates the relationship between metacognitive language learning strategies (MLLS) and gender and achievement of EFL students. Metacognitive language learning strategies are crucial for students of English as a foreign language to learn effectively. The theoretical issues discuss metacognitive language learning strategies in particular, and language learning strategies (LLS) in general. The practical research took place at the English language department at Farhat Abbes University, Sétif, Algeria, with third year students learning English as a foreign language. The study hypothesized that there is a positive correlation between metacognitive language learning strategies use and achievement. Two main parts following a qualitative design constitute the body of the present research. The first part uses the Metacognitive Language Learning Strategies Questionnaire (MLLSQ) to account for differences in the reported frequency of metacognitive strategies use across all the students, and across gender differences. The second part uses interviews to account for the use of these strategies at the individual level, in their relation to the students’ gender and achievement in language learning. The results of the first part revealed a significant use of metacognitive strategies among all the students and significant differences between male students and female students in the frequency of use of these strategies. Moreover, the results of the second part reflected more significant differences in the use of Metacognitive strategies at the level of gender and learning achievement. The study concludes by bringing together key findings and some suggestions for further research.