This study aims to develop and evaluate the feasibility of a teaching module based on Project-Based Learning (PjBL) assisted by Plickers on ecosystem material to improve the creative thinking skills of fifth-grade elementary school students. This study employed a Research and Development (R&D) method using the ADDIE development model, consisting of five stages: Analysis, Design, Development, Implementation, and Evaluation. The research subjects were 25 fifth-grade students at SD Negeri 69 Krui. Data were collected through expert validation sheets, teacher and student response questionnaires, observations, and creative thinking tests administered through pretest and posttest. The effectiveness of the developed module was analyzed using the Wilcoxon Signed-Rank Test, N-Gain, and effect size. The results showed that the developed module achieved an overall validity score of 93.08%, categorized as highly valid, with material validity of 94%, media validity of 94%, and language validity of 91.25%. The practicality test obtained scores of 90% based on teacher responses and 87% based on student responses, both categorized as highly practical. The effectiveness test indicated an improvement in students' creative thinking skills, with the mean pretest score increasing from 62.96 to 81.32 on the posttest. The Wilcoxon test yielded a significance value of 0.001 < 0.05, while the N-Gain score was 0.5426, categorized as moderate, and the effect size was 0.870, indicating a large effect. Therefore, the PjBL-based teaching module assisted by Plickers is highly valid, highly practical, and effective for improving the creative thinking skills of fifth-grade elementary school students on ecosystem material.