The terrorist attacks of September 11, 2001, initiated a shift toward a comprehensive, or "all-hazards," framework of emergency preparedness in the United States. Since then, the threat of H5N1 avian influenza, the severe acute respiratory syndrome epidemic, and the 2009 H1N1 influenza pandemic have underscored the importance of considering infectious events within such a framework. Pediatric emergency departments (EDs) were disproportionately burdened by the 2009 H1N1 influenza pandemic and therefore serve as a robust context for evaluation of pandemic preparedness. The objective of this study was to explore pediatric ED leaders' experiences with preparedness, response, and postincident actions related to the H1N1 pandemic to inform future pandemic and all-hazards planning and policy for EDs. The authors selected a qualitative design, well suited for exploring complex, multifaceted organizational processes such as planning for and responding to a pandemic and learning from institutional experiences. Purposeful sampling was used to recruit medical directors or their designated physician respondents from pediatric emergency medicine training institutions representing a range of geographic regions across the United States, hospital types, and annual ED volumes; snowball sampling identified additional information-rich respondents. Recruitment began in May 2011 and continued until thematic saturation was reached in January 2012 (n = 20). Data were collected through in-depth individual phone interviews that were recorded and professionally transcribed. Using a standard interview guide, respondents were asked open-ended questions about pandemic planning, response, and institutional learning related to the H1N1 pandemic. Data analysis was performed by a multidisciplinary team using a grounded theory approach to generate themes inductively from respondents' expressed perspectives. The constant comparative method was used to identify emerging themes. Five common themes characterized respondents' experiences with pandemic planning and response: 1) national pandemic influenza preparedness guidance has not fully penetrated to the level of pediatric emergency physician (EP) leaders, leading to variable states of preparedness; 2) pediatric EDs that maintained strong relationships with local public health and other health care entities found those relationships to be beneficial to pandemic response; 3) pediatric EP leaders reported difficulty reconciling public health guidance with the reality of ED practice; 4) although many anticipated obstacles did not materialize, in some cases pediatric EP leaders experienced unexpected institutional challenges; and 5) pediatric EP leaders described varied experiences with organizational learning following the H1N1 pandemic experience. Despite a decade of investment in hospital preparedness, gaps in pediatric ED pandemic preparedness remain. This work suggests that raising awareness of pandemic planning standards and promoting strategies to overcome barriers to their adoption could enhance ED and hospital preparedness. Helping hospitals better prepare for pandemic events may lead to strengthened all-hazards preparedness.