This study aimed at exploring how problem posing enhances grade 8 students' conceptual understanding of mathematics in a private school in Chitral, The participants of this research were 40 students of grade 8 and their regular mathematics teacher. For data collection, I observed five lessons in reconnaissance stage to get an insight into the existing teaching approaches and sources of mathematical problems the mathematics teacher used in the classroom. I also conducted an interview or had informal talks with the participant teacher before and after the lessons. Then, I conducted demo lessons during the pre-intervention stage to help the participant teacher improve his general pedagogical content knowledge for developing students' conceptual understanding. Afterward, during the intervention stage, the participant teacher and I conducted nine lessons in three cycles using problem posing as the main strategy. Before and after the teaching participant teacher and I had collaborative reflective dialogues on our experiences of implementing problem posing in the class. During the reconnaissance stage, I found that participant students had never experienced problem posing before the reported study. In the first cycle of the intervention stage, we started problem posing with reformulation of the existing word problems. In the second cycle, students analyzed, solved and critiqued word problems which they had collected from different sources. Finally, students posed word problems using imaginary situations following guided instruction. Data collection and data analysis process went simultaneously during the action research cycles. At the end of each cycle, we analyzed the problem posed by the students by looking at their solvability, complexity and originality (Silver and Cai, 2005; Lin & Leng, 2008). Analysis of the data shows that students developed their problem posing skills, as well as critiquing the given problems. This study found problem posing as a promising teaching strategy to develop students' conceptual understanding in mathematics.