The personality profile of 44 youngsters (24 males, 20 females; mean age 11 years, 3 months) with neurofibromatosis type 1 (NF1) was compared with a group of 220 non-NF1 control youngsters (matched on age and gender). Personality characteristics of each youngster were rated by both parents, using the California Child Q-set (CCQ); [Block and Block, 1980]. The scores on eight personality dimensions were compared, i.e., Extraversion, Agreeableness, Conscientiousness, Emotional Stability, Openness, Motor Activity, Irritability, and Dependency. Moreover, personality of NF1 youngsters was related to IQ level, severity of medical problems, the presence or absence of visible cosmetic disfigurements, and de novo versus familial origin of NF1. The personality profile of NF1 youngsters was markedly different from the non-NF1 youngsters. Compared to the 220 control children, they were equally agreeable, but less conscientious, less emotionally stable, less open for new experience, with less motor activity, and more extravert, more dependent, and more irritable. Personality characteristics were similar for children with maternally or paternally inherited NF1, or for children with a new mutation. There was no association with gender, the severity of medical and cosmetic problems, and IQ. © 2003 Wiley-Liss, Inc.