This study collected data about developmental problems in a cohort of children with congenital central hypoventilation syndrome. In 2003, in Switzerland, 11 children with this disease were registered. Nine of them gave their informed consent to participate in the study and were examined. Clinical assessments were conducted, including examinations of neuropsychological, behavioral, and adaptive functions using Kaufman-Assessment Battery for Children, Child Behavior Checklist, and Vineland Adaptive Behavior Scales. The mean age (+/- standard deviation) was 7.5 +/- 2.5 years. The cognitive tests showed problems in working memory functions with a near-to-normal full-range intelligence quotient (87.4 +/- 23.3). The children showed normal values (t-values < 67) on problem scales of behavior, although 5 of the 9 children showed elevated values on the attention and on the social interaction problem scales. Adaptive function problems were identified in communication and daily living skills.