The aim of this study is to analyse attitudes, perceptions of teacher self-efficacy and collaborative practices and teachers' opinions of the most appropriate placement for students with severe/permanent SEN. The methodology involves a survey based on a questionnaire administered to teachers in three school groups in the central region of mainland Portugal, including scales for the assessment of attitudes towards inclusion, perceptions of teacher self-efficacy and collaboration between teachers. The data was processed using descriptive and inferential statistics with the aid of SPSS software. The results indicate that the teachers have favourable attitudes towards inclusion and a high perception of self-efficacy, and also provide evidence of collaborative practices. In addition, a positive and statistically significant relationship between teachers' attitudes and perceptions of self-efficacy with regard to inclusion was identified, affirming a statistically significant relationship between these variables and teachers' opinions of the most appropriate placement for students with severe/permanent SEN. What is still at stake is that, despite inclusive policies, the placement of students with SEN in regular classrooms can still be influenced by the type of SEN. It was also noted that the diversity of students, the reinforcement of collaborative practices represent challenges for the inclusion of these students.