Objective: To describe the burden of care experienced by our pediatric health care facility inNewYork,NewYork, from May 3, 2009, to July 31, 2009, during the novel influenza A(H1N1) pandemic that began in spring 2009. Design: Retrospective case series. Setting: Pediatric emergency departments and inpatient facilities of New York-Presbyterian Hospital. Patients: Children presenting to the emergency departments with influenza-like illness (ILI)andchildren aged18 years or younger hospitalized with positive laboratory test results for influenza A from May 3, 2009, to July 31, 2009. Main Outcome Measures: Proportion of children with ILI who were hospitalized and proportion of hospitalized children with influenza A with respiratory failure, bacterial superinfection, and mortality. Results: When compared with the same period in 2008, the pediatricemergencydepartmentsexperiencedanexcess of3750visits(19. 9%increase). Overall,27.7%of visitswere for ILI; 2.5% of patients with ILI were hospitalized. Of the 115 hospitalized subjects with confirmed influenzaA(median age, 4.3 years),93(80.9%)hadunderlying conditions. Four(3.5%)hadidentified bacterial superinfection,1(0.9%) died, and 35 (30.4%) were admitted to a pediatric intensive care unit; of these 35 patients, 11 had pneumonia and required mechanical ventilation, includinghigh-frequency oscillatory ventilation (n=3). Conclusions: At our center, 2.5% of children with ILI presenting to the emergency departments during the first wave of the 2009 novel influenza A(H1N1) pandemic were hospitalized. Of the 115 hospitalized children with confirmed influenza A, 9.6% had respiratory failure and 0.9% died. These findings can be compared with the disease severity of subsequent waves of the 2009 novel influenza A(H1N1) pandemic.