The literature provides several examples of anxiety symptoms questionnaires for children. However, these questionnaires generally contain many items, and might not be ideal for screening in large populations, or repeated testing in clinical settings. The Spence Children’s Anxiety Scale (SCAS) is an extensively used and evaluated 44-item questionnaire developed to assess anxiety symptoms in children, and provides a sound base for the development of an abbreviated anxiety symptoms questionnaire. Although methodological standards have been presented in how to develop abbreviated questionnaires, previous studies have often suffered from several limitations regarding validating procedures. Guided by these methodological standards, the current study aimed at developing an abbreviated version of the SCAS, while retaining the content, convergent, and divergent validity of the original scale. A school-based sample (n = 750) was used to reduce the number of items, and an independent school-based sample (n = 371) together with a clinical sample (n = 93), were used to validate the abbreviated scale. The abbreviated version of the SCAS contained 19 items, it showed a clear factor structure as evaluated in the independent sample, and it performed as good as the original questionnaire regarding classification accuracy, convergent, and divergent validity. In our view, the abbreviated version is a very good alternative to the original scale especially for younger children, in initial screening, or in order to reduce response burden.