Children with externalizing behavior problems are likely to show poor school achievements, problems in social interactions with teachers and peers and an elevated school-related stress. Though class climate is a meaningful variable to explain school achievements and aspects of emotional well-being, there are hardly any studies that consider class climate from the perspective of children with externalizing problems. The present study examines the question how children with externalizing problems assess class climate. Furthermore, the study analyzes the possible impact of internalizing comorbidities. The sample of fourth grade primary school children (N = 119) includes 27 students with hyperactive-inattentive and 47 children with dissocial symptoms. Data are analyzed using ANOVAS and hierarchical linear regressions. Externalizing problems coincide with negative assessments of class climate, which are even more negative among students with dissocial symptoms and internalizing comorbidities. While hyperactive-inattentive children primarily focus on a few aspects of class climate (especially unfair teacher decisions), children with dissocial symptoms show more global negative perceptions. The results point to low levels of social participation of children with externalizing problems. Future studies should consider the potential importance of class climate for school-based diagnostics and behavior modification.