This study aimed to investigate the relationships among high school students' approaches to learning science, perceptions of classroom learning environment, and achievement goals. The participants of the study included 800 high school students from 9th to 12th grade in three public schools. A conceptual model constructed based on literature were tested with structural equation modeling. The analysis of the data collected in this study supported the hypothesized model. The findings revealed that students' perceptions of classroom environment and mastery-approach goals affected positively their deep approaches to learning science. In this study, the mediated effect of mastery-approach goals was observed. Mastery approach goals increased the effect of the perceptions of classroom learning environment on deep approaches to learning science. Moreover, it was found that performance-approach, performance-avoidance and mastery-avoidance goals were positively associated with surface-approaches to learning science. Finally, in this study, the positive effect of students' perceptions of classroom learning environment on their mastery-approach goals was observed. The implications of the study for teaching and learning were discussed.