The current study investigated the extent to which metacognitive writing strategies are used by Omani EFL grade twelve students. It also explored if there is a significant relationships between grade 12 students' use of metacognitive writing strategies and their language performance. In addition, it examined gender differences in the use of these strategies. The sample of the study was 263 Omani EFL grade twelve students from Batinah North Governorate in the academic year 2018/2019. Metacognitive Strategies of Writing Survey (MSWS) and semi-structured interviews were used to collect data. The results of the study revealed that students use the three types of metacognitive writing strategies; planning, monitoring and evaluating at high frequencies. However, the findings revealed no significant relationship between students' use of the three types of metacognitive strategies and their language performance. Moreover, students differ in terms of gender in using metacognitive writing strategies. Female students tend to use more metacognitive strategies in writing compared to male students. In light of these findings, implications for practice and future studies have been recommended.