Previous studies pointed out that dealing with difficult behaviour is perceived by teachers as a major challenge in inclusive settings. However, research on the students' perception of the classroom behavioural climate (CBC) is rare. Therefore, this study aims to examine students' perceptions of CBC and to identify predictors of CBC as well as associated variables. The sample consists of 650 German students from secondary schools (5th-9th grade) of whom 83 students are diagnosed with special educational needs (SEN). CBC was measured via four subscales ('students' possibilities to study and concentrating on teaching', 'disruptive behaviour', 'physical and psychological safety' and 'caring for the physical environment'). Results show significant differences in students' perceptions of CBC between students from different school tracks. Furthermore, gender (being male) and SEN (having a) predict the perception of 'physical and psychological safety'. Additionally, social inclusion, emotional experience as well as teacher support and care are associated with CBC. Accordingly, a positive CBC is important for the successful implementation of inclusive education: while diversity in classrooms is a challenge for behavioural climate, poor behavioural climate may also pose specific barriers to learning for some students with SEN and thus is a general challenge for equity in inclusive classrooms.