This study had three goals: to examine differences between the amounts of time kindergarten teachers reported spending in instructional practices and their perceptions of students' social competence; to investigate differences between child and teacher characteristics and teachers' instructional practices; and to examine differences between demographic variables of children and teachers' perceptions of kindergartners' social competence. Data included information on 4,663 kindergarten children and 1,143 teachers from the Early Childhood Longitudinal Study, Kindergarten Cohort of 1998–1999 (ECLS-K). Results revealed differences in teachers' years of experience and the amount of time they reported spending in instructional practices. However; no differences were found based on teachers' certification and education level. Findings suggested differences in teachers' reported instructional practices and perceptions of children's social competence based on children's demographic characteristics. Differences also existed in teachers' perceptions of children's social competence based on the amount of time they reported spending in instructional practices.