This research aimed to verify the effectiveness of using the model-based thinking strategy in developing first-grade high school students’ physical concepts and inquiry thinking skills. To achieve this goal, the research used the experimental approach with a quasi- experimental design for the experimental and control groups. The sample of the study consisted of 67 students in the first grade of high school, and it was divided into two groups: the experimental group 33 students (who studied using the model-based thinking strategy) and the control group 34 students (who studied conventionally). The study used the following tools: the physical concepts test and the inquiry thinking skills test. The results of the current research revealed that there are statistically significant differences between mean scores obtained by the experimental and control groups in the physical concepts test as a whole and its different levels of knowledge favoring the experimental group, and there are statistically significant differences between mean scores obtained by the experimental and control groups in the inquiry thinking test as a whole and its different skills favoring the experimental group, and there is a positive statistically significant relationship between the development of physical concepts and inquiry thinking skills among the students of the experimental group. Finally, the research presented some recommendations and proposals, including conducting more studies on model-based thinking strategy, inquiry thinking skills, and physical concepts in various disciplines and age stages.