We examined relations between parent involvement and kindergarten students' behavior problems in classrooms with varying levels of teacher emotional support. Multi-informant data were collected on "n" = 255 low-income Black and Hispanic students, and "n" = 60 kindergarten classrooms in the baseline year of an intervention trial. Hierarchical linear models revealed a moderated negative effect between parents' home-school communication and teacher emotional support on student behavior problems in kindergarten, as well as negative associations between school-based involvement and behavior problems. For children in classrooms with less teacher emotional support, greater communication between home and school was related to higher levels of behavior problems. Among children in classrooms with more teacher emotional support, this negative relationship was attenuated. Results illuminate the need to consider parent involvement within the context of classroom practices. (Contains 1 figure and 3 tables.)