The repetitive behaviour questionnaire (RBQ) (Turner, 1995) is one of the three most commonly used interview/questionnaire measures of repetitive behaviour (Honey et al., in preparation). Despite this there is a scarcity of information concerning its structure, reliability and validity. The psychometric properties of the RBQ were examined when used with children with an autism spectrum disorder, children of typical development and children with a learning disability. The questionnaire was found to examine two valid and reliable factors of repetitive behaviour and to have good levels of concurrent and construct validity. This novel study provides researchers and clinicians with information necessary to make decisions about the RBQ's utility and for the evaluation of conclusions drawn from existing research, which has used the RBQ. (Contains 6 tables and 1 figure.)