Worry is a common symptom in various psychiatric problems and the key symptom of generalised anxiety disorder (GAD). The Penn State Worry Questionnaire (PSWQ) is the most widely used self-report scale for measuring worry. The present study provides normative data for the Dutch version of the PSWQ for a large community sample and a clinically referred sample of patients with GAD. Norms are not only provided for the original 16-item version, but also for an abbreviated 11-item version, which only consists of the positively worded items and has been shown to be a promising alternative to the full-length version. The percentile scores obtained for the community sample and the clinical GAD sample did not show much overlap, and this appeared true for the full-length as well as the abbreviated version of the PSWQ. These normative data seem suitable for differentiating between normal and abnormal manifestations of worrying and for evaluating the efficacy of treatments for GAD. (Netherlands Journal of Psychology, 65, 69-75.)