Objective: The study examined the concordance among rating sources on attention problems of elementary school-aged children. Method: A randomly selected sample ("N" = 841) of children was rated by the physical educators, the teachers, and the parents, using the Attention Scales of the Motor Behavior Checklist (MBC), the Teacher Report Form, the Child Behavior Checklist, and the ADHD-Rating Scale-IV (ADHD-RS-IV). Results: Convergent validity of the Lack of Attention Scale of the MBC with the corresponding subscales was supported. Correlations were higher between teachers' ratings and between physical educators' and teachers' ratings than between physical educators' and parents' ratings or between teachers' and parents' ratings. Conclusion: Findings underscore the importance of taking the child's settings and observer influences into account and suggest that MBC is a new promising instrument for screening attention problems in school settings. (Contains 2 tables.)