"Low-Level Lead Exposure and Children's Cognitive Function in the Preschool Years" by Bellinger et al (Pediatrics. 1991:87:219-227) has an error in Fig 2 on page 225. The error bars for the mean change in score for children in the "low" lead group should cover an interval that is approximately 50% larger than that indicated. The correct boundaries for mean ± SE are 12.3 and 1.2 points.