This study examined the associations among child demographic variables, teacher perceptions of parent-teacher and student-teacher relationship quality, and teacher perceptions of children's academic abilities in an ethnically diverse sample of 607 academically at-risk first grade children. Relative to relationships with African American children and parents, teachers rated their relationships with White and Hispanic children and parents more positively. Measures of relationship quality added unique variance to teachers' perceptions of children's abilities, controlling for parent educational level and measured ability. Relationship variables fully mediated the association between African American status and teachers' perceptions of children's abilities. Implications of the findings for teacher in-service and professional development and for parent involvement programs are discussed.