Children with neurologic and neurodevelopmental conditions are at increased risk for severe outcomes from influenza, including death. In April 2011, the Ohio Department of Health and CDC investigated an influenza outbreak that began in February 2011 in a residential facility for 130 children and young adults with neurologic and neurodevelopmental conditions. This report summarizes the characteristics and clinical courses of 13 severely ill residents with suspected or confirmed influenza; 10 were hospitalized, and seven died. Diagnosis is challenging in this population, and clinicians should consider influenza in patients with neurologic and neurodevelopmental conditions who have respiratory illness or a decline in baseline medical status when influenza is circulating in the community. Prompt testing, early and aggressive antiviral treatment, and antiviral chemoprophylaxis are important for these patients. When influenza is suspected, antiviral treatment should be given as soon as possible after symptom onset, ideally within 48 hours. Treatment should not wait for laboratory confirmation of influenza. During outbreaks, antiviral chemoprophylaxis should be provided to all residents of institutional facilities (e.g., nursing homes and long-term- care facilities), regardless of vaccination status. Residential facilities for patients with neurologic and neurodevelopmental conditions are encouraged to vaccinate all eligible residents and staff members against influenza.