In children with Williams-Beuren syndrome (WBS), disturbed behaviors (neurotic, antisocial, and hyperactive) [Arnold et al., 1985: Dev Med Child Neurol 27:49-59; Udwin et al., 1987: J Child Psychol Psychiat 28:297-309] have been described. To study the behavior disturbances and social-emotional adjustment in children with WBS, a group of N = 19 patients was compared with a control group, matched for age, gender, and nonverbal reasoning abilities. Parents were asked to assess the children's behavior in terms of a list of 20 items of the Child Behavior Checklist (CBCL) [Achenbach and Edelbrock, 1983: Manual for the Child Behavior Checklist] and the Vineland Social Maturity Scale (VSMS) [Lüer et al., 1972: Kurzform der Vineland Social Maturity Scale]. As compared with the control group, children with WBS differ significantly in their social behavior towards strangers. They exhibit no reserve or distancing behavior and would, for instance, follow a stranger without hesitation. They are described as showing a hypersensitivity to sounds that is more pronounced than in the control group. Finally, they are found to be significantly less well-adjusted socially than the control individuals.