The relationship among students' reading performance, their behavior (task-focused behavior, emotional stability, and compliant behavior) in the classroom, and the teacher's skills was investigated in 66 third-grade classrooms. Results from this study showed the students' reading performance and their behavior in the classroom are all significantly interrelated. Better reading performance at the beginning of the school year goes with better behavior at the end of the school year. In turn, better behavior at the beginning of the school year goes with better reading performance at the end of the school year. The teacher can improve the behavior of the students by providing high-quality reading instruction. Some teacher skills have differential effects, however, on the various behavioral aspects. The implications for the educational practice as well as for future research are discussed.