This research studied the effectiveness of the simulation-based learning assisted with scaffolding approach to address students' misconceptions (MCs) about projectile motion. The five MCs were related to the direction of the force acting on an object (MC1), the acceleration of an object at the top of the trajectory (MC2), the directions of velocity and acceleration during projectile motion (MC3), the time of flight of objects (MC4), and the relationship between the range of projectile motion and angle of projection (MC5). This study was a pre-experimental design using both quantitative and qualitative data. The sample comprised 35 tenth-grade Thai high school students who were chosen using the cluster sampling technique. The teaching method consisted of three steps: a briefing, simulation, and debriefing. Each step was assisted with scaffolding to guide and help the students. The MCs tests consisted of five multiple-choice questions with a four-tier diagnostic test, and the tests were used as a pre-test, end-of-class test, and end-of-topic test. Six semi-structured interview questions were used to obtain in-depth data. The results indicated that MC1, MC2, MC3, MC4, and MC5 were addressed by 11.1%, 85.7%, 57.2%, 57.2%, and 61.5%, respectively, at the end-of-topic test. Students who had MCs in the pre-test changed their understanding of the concepts in MC2, MC3, MC4, and MC5 by 57.1%, 14.3%, 28.6%, and 53.8%, respectively. None of the MC students in MC1 understood the concept at the end-of-topic test. Nevertheless, the overall results showed increased students' understanding of all conceptions.