Students' engagement is known to be associated with academic success and to prevent school dropouts. While many studies have considered this variable when examining school trajectories, more research is needed to investigate the factors that may sustain and promote engagement in school, regarded as a multidimensional construct (affective vs. cognitive vs. behavioral engagement). In the present cross-sectional study, associations between students' perceptions of "school climate" dimensions and their level of engagement were explored. The differential effects on these associations of sex and social background were also examined. Results from a sample of 955 high-school students showed that a model incorporating six dimensions of perceived school climate explained a large proportion of the variance in students' engagement, especially affective engagement. The perceived climate of relations between teachers and students appeared to be highly predictive of students' engagement. Analyses also revealed that the predictiveness of school climate factors for affective, cognitive and behavioral engagement varied slightly according to sex and social background. These results highlight important levers associated with students' engagement in school.