Inclusion is one of the most important and emerging areas for school improvement. The purpose of this study was to explore the perception of high school students with the aim of determining whether there is a shared and inclusive education within their schools. An explanatory model was developed, based on the responses of 365 students from the participating high school, using a scale on inclusion that had already been used in the Spanish context. The results showed a high correlation between the perception of inclusion and factors such as the perception toward the supportive teacher, the need for help and the satisfaction perceived in the classroom. We analysed which potential factors proved to be good predictors of the results associated with the perception of educational inclusion obtained using this scale. The results showed that the students' perceptions of inclusion evolved negatively over different grades. In contrast, it was found that their perception toward the teachers was mediated by the existence of a special need and age, and was higher in those students who had experienced the Support Teacher directly or indirectly.