To examine the concordance of mother and teacher ratings of children born at different birth weights on measures of school functioning, behavioral problems, and social competencies, we used a prospective cohort study involving children in two previously studied multisite birth cohorts whom we recontacted at 8 to 10 years of age. This provided a multisite sample of 784 low birth weight children and 334 normal birth weight children. Teacher reports of children's behaviors were obtained from 80% of the 1400 teachers contacted. We found that birth weight and neonatal health were associated with both maternal and teacher reports; that maternal characteristics, e.g., low levels of education and poor mental health, were associated with the greatest discrepancies in reports; and that although mothers' reports of objective measures were accurate, their assessments of behavioral problems and social competence often differed from those of teachers.