The Aut-Eat Questionnaire (AEQ) provides a novel and comprehensive assessment of eating problems and patterns in children with ASD. To establish the internal consistency and discriminant validity of the AEQ, parents of children with ASD (n = 105, M[subscript age] = 40.85, SD = 15.67 months) or typical development (TD; n = 98, M[subscript age] = 50.33, SD = 16.50 months) completed the AEQ. Questionnaire construction, content validity, factor analysis, internal consistency and discriminant validity are reported. The AEQ was reliable with high internal consistency in most domains. Significant differences were found between groups in all domains. The AEQ is a reliable and valid tool and may help to characterize eating difficulties in this population.