In situations with visible threats to children's health, pediatric health care providers must be prepared to communicate the health risks of environmental exposures. Several factors influence the effectiveness of such discussions: whether the individual providing the information is considered a reliable source, the familiarity of the physician and parent/guardian with these issues, and the limited research specifically assessing risk of exposure in childhood. This article describes the theory behind effective risk communication using examples from events following September 11, 2001. It shares lessons learned and provides a template for risk communication that can guide pediatric providers.