Cornelia de Lange syndrome (CdLS) is a multiple congenital anomaly/mental retardation syndrome, characterized by distinctive facial features, generalized hirsutism, growth and cognitive dysfunction, microcephaly and limb abnormalities. Currently mutations of three different genes, NIPBL, SMC1A, and SMC3, are known to be related to the CdLS phenotype with an overall detection rate of about 50%. Few data are available regarding the level of autonomy in everyday life of CdLS patients. Due to the collaboration of the Italian parents' support group, we collected information regarding clinical and behavioral problems and everyday abilities of 45 CdLS patients between 13 and 39 years, using a specific multi-item questionnaire. To better analyze clinical information we divided our patients into three groups according to age: 13–20, 21–29, and over 30 years. Data from clinical, malformative and behavioral problems were not significantly different from those described for CdLS patients. Regarding personal autonomies this study showed the significant limitations of these individuals. It is interesting to observe that patients between 21 and 29 years, showed the best performance, while those over 30 had more severe difficulties. We suggest that these data be interpretated as a minimum level of autonomy achievable for CdLS adolescent/young adults, as the level of care, rehabilitation and stimulation of these patients has increased in the last 30 years. © 2009 Wiley-Liss, Inc.