Teachers' knowledge of children's exposure to family risk factors was examined using the Family Risk Factor Checklist-Teacher. Data collected for 756 children indicated that teachers had accurate knowledge of children's exposure to factors such as adverse life events and family socioeconomic status, which predicted children's mental health problems at 1 year follow-up. For children at high teacher-rated risk, odds ratios ranged from 3.04 to 7.46, after adjusting for prior mental health problems. Teachers had poor knowledge of internal family functioning, such as conflict, parenting practices, or parental drug abuse. The findings suggest that asking teachers to report children's exposure to particular family risk factors is a feasible method for identifying children for selective interventions, but improved family-school communication may further enhance this process.