ABSTRACTThis study investigates the impact of problem‐posing on the mathematical proficiency and engagement of 56 Developmental Mathematics (DM) students enrolled in a noncredit college mathematics course. Using a quasi‐experimental design, one of two existing classes was selected as the experimental group and received a 5‐week intervention focused on problem‐posing with word problems. The other class served as the control group, receiving the same instruction but without engaging in problem‐posing. Both the experimental group of 25 participants and the control group showed significant improvement on the posttest compared to the pretest in mathematical proficiency, with the experimental group demonstrating more pronounced growth. Further analysis, which divided students into three subgroups based on pretest scores, revealed that students in the lower two subgroups of the experimental group significantly outperformed all other groups on the posttest. A qualitative analysis identified potential reasons for the growth in these subgroups. Students in the experimental group built confidence by first mimicking previous problems and verifying their calculations. They also personalized their problem‐posing experiences, which contributed to increased engagement, persistence, and deeper understanding of the material, ultimately enhancing their mathematical proficiency. The study demonstrates that DM students are both capable of and willing to engage in problem‐posing.