Objective: To report neurologic complications in a large population of pediatric lung transplantation patients. Methods: A retrospective review of the first 135 patients to undergo lung transplantation at St. Louis Children's Hospital from July 1990 to December 1997. Results: Sixty-one (45%) patients had neurologic complications. The most common presenting symptoms were seizures (27%), followed by encephalopathy, headache, depression, and focal neurologic deficits. Cyclosporine toxicity (7%) and hypoxia-ischemia (7%) constituted the most commonly identified etiologies, followed by stroke, metabolic, and infectious causes. Risk factor analysis found that patients with interstitial lung disease had a higher frequency of hypoxic-ischemic events and patients with seizures had significantly elevated trough cyclosporine levels. Patients with stroke and hypoxia had a poor neurologic prognosis, whereas patients with cyclosporine toxicity uniformly had a good outcome. Conclusions: Neurologic complications occur frequently after lung transplantation in pediatric patients, with seizures being the most common presenting symptom. Except in patients with stroke and hypoxia, prognosis is generally favorable. Seizures not accompanied by an irreversible structural etiology are unlikely to require long-term treatment with antiepileptic medications. Cyclosporine neurotoxicity typically resolves without requiring discontinuation of immunosuppressive therapy.