Reflective journaling has been acknowledged as a valuable tool for fostering active learning among students. Many studies have examined its effects on second language (L2) students' skills. However, a limited number of studies have investigated its impact on L2 undergraduate students’ writing practices, particularly in the Saudi context. Additionally, the exploration of L2 students’ perceptions of reflective journaling in academic writing has received scant attention. Therefore, this study aimed to explore how reflective journals contribute to developing L2 Saudi students’ academic writing and their perceptions about using reflective journals in writing. A qualitative research approach was employed to collect data from 13 female Saudi students enrolled in an academic writing course at a public Saudi university. The primary data sources for the study were reflective journal entries and semi-structured interviews. The qualitative content analysis of the collected data revealed that most students found reflective journaling helpful for their writing practices. Specifically, it assisted them in exploring the complexity of academic writing, monitoring their writing practices to refine their skills, and cultivating an academic writer identity. However, students reported that they faced challenges while writing reflective journals, which were time-consuming and lacked constant feedback on their journal entries. The study concludes with several recommendations for L2 writing instructors and researchers.