Anxiety is highly prevalent in autistic children. Yet interpretation biases implicated in anxiety in non-autistic individuals have received little research attention in this group. Twenty-two autistic children and 25 typical children completed an ambiguous scenarios interview and questionnaire-based measures of anxiety. A subsample of mothers completed parent-report and adult relevant versions of the interview and anxiety questionnaires. Autistic children self-reported similar interpretations of ambiguous scenarios, and similar levels of anxiety, to their typical peers. In contrast, mothers of autistic children reported greater levels of anxiety, and more negative interpretations of ambiguous scenarios in both their children and themselves, relative to mothers of typical children. These data highlight the importance of including autistic children's self-reports when measuring and treating anxiety.