Since writing is characterized with a cognitive nature, one practical approach to improve EFL learners' writing skill is to resort to inquiry-based learning approaches such as problem-based learning (PBL) which is characterized with a high cognitive demand and often contribute to high retention of knowledge. This study aimed at exploring Iranian EFL learners’ perceptions of problem-based learning. In so doing, a content analysis design was used within the qualitative paradigm. The participants consisted of 15 (8 females and 7 males) advanced EFL learners who participated in the study through purposive sampling from different language institutes in Tehran. The data were gathered through a semi-structured interview. Data analysis was conducted through thematic analysis. Based on the interview data, the following themes were extracted: Engagement, collaboration, personal preferences, sharing knowledge, novelty, less supportive teachers, joyful learning process, and use of adequate technologies, time requirements, affecting vocabulary learning, changing students' perception about the learning process and the teachers' role. The results have some implications for EFL teachers and learners, and curriculum planners. Key Words: Collaboration, Engagement, Writing, Problem-based Learning. تفاصيل المقالة