The aim of this study was to describe students' perceptions of their psychosocial school environment and to examine the associations between such perceptions and students' perceived school performance. Our analyses were based on data from the Health Behaviour in School-Aged Children 2006 study, involving responses by Finnish students from grades 7 and 9. The results indicated that students' perceptions of their school environment were fairly positive, but that a remarkably large proportion of the students reported negative attitudes towards school. School engagement, school strain, and teacher-student relations were found to be the most influential predictors in the psychosocial school environment regarding perceived school performance; as were the grade and educational aspirations out of the selected background factors. The findings imply that despite good academic achievement in Finnish comprehensive schools, there is still a need to improve students' school engagement and their satisfaction with school. (Contains 6 tables.)