Aicardi syndrome is an X-linked-dominant condition characterized by infantile spasms, agenesis of the corpus callosum, and chorioretinal lacunae. We reviewed the Aicardi Syndrome Foundation's compilation of family-based, self-reported questionnaires for the year 2000. Information was obtained from 77 females with Aicardi syndrome regarding developmental milestones, seizure frequency, seizure classification, antiepileptic drug use, and medical problems. Patient ages ranged from 1 to 25 years (mean = 7.2 years). All patients were significantly developmentally delayed with milestones ranging from 2 to 36 months. Of the patients, 91% attained milestones no higher than 12 months. Seizures were reported in 92% of patients and occurred daily in 67%. Infantile spasms were the most common seizure type observed in 17%, although a variety of other seizure types were also reported. Multiple antiepileptic drugs were used in these patients with 73% of patients taking two or more antiepileptic drugs. Five patients had a vagal nerve stimulator implanted, and one patient underwent a hemispherectomy. The most common medical problems cited included scoliosis, constipation, gastroesophageal reflux, aspiration pneumonia, and otitis media, but overall health was perceived to be good. Our review demonstrates the spectrum of developmental disabilities, epilepsy severity, and prognosis in a large group of Aicardi patients.