This study aimed to examine the relationship between mathematical modelling and reflective thinking and to examine the effects of employing mathematical modelling processes on perception of mathematical modelling competencies and reflective thinking skills for real-life problem solving of gifted students participating in Project Production and Management Program at Turkish Science and Art Centers. Correlational path analysis of 300 students data revealed that Mathematical modelling is a significant predictor of reflective thinking skills, and the constructed model was found to be of a good fit with excellent path coefficients. Experimental design with pre-post-maintenance-tests with comparison group was employed with 60 students purposefully selected chosen from the above regression study. Reflective thinking and mathematical modelling levels of experimental group students who employed mathematical modelling processes for Project Production and Management increased significantly more from pre- to post-tests, and the significant difference was found to be maintained.