Sturge-Weber syndrome (SWS) is a neurocutaneous disorder characterized by cutaneous facial angioma, leptomeningeal angioma associated with seizures and other neurologic complications including mental retardation, and glaucoma. Only limited information about long-term outcome, including the societal integration of adult patients, is available in the literature. Data on 52 adults with SWS, ages 18-63 years, ascertained through the Sturge-Weber Foundation, were obtained via written questionnaires, telephone interviews, and reviews of medical records. The distribution of port-wine stains (cranial 98%, extracranial 52%) and the prevalences of glaucoma (60%), seizures (83%), neurologic deficit (65%), and other complications were established. The age of onset of glaucoma (0-41 years), the age of onset of seizures (0-23 years), and the correlation between the distribution of port-wine stains and the prevalence of seizures was identified. The relationship between the age of onset of seizures and seizure control was established. In those with and without seizures, the prevalences of developmental delay (43% vs. 0%), emotional and behavior problems (85% vs. 58%), special education requirements (71% vs. 0%), and employability (46% vs. 78%) were analyzed. Overall, 39% were financially self-sufficient, and 55% were or could be married. Ten participants produced 20 liveborn offspring; 17 were healthy, and tuberous sclerosis, a café-au-lait spot, and a "birthmark" were found in 1 child each. The results of this study can be used for genetic counseling in Sturge-Weber syndrome.