The Autism Spectrum Quotient-Children's Version (AQ-Child) is a parent-report questionnaire that aims to quantify autistic traits in children 4-11 years old. The range of scores on the AQ-Child is 0-150. It was administered to children with an autism spectrum condition (ASC) (n = 540) and a general population sample (n = 1,225). Results showed a significant difference in scores between those with an ASC diagnosis and the general population. Receiver-operating-characteristic analyses showed that using a cut-off score of 76, the AQ-Child has high sensitivity (95%) and specificity (95%). The AQ-Child showed good test-retest reliability and high internal consistency. Factor analysis provided support for four of the five AQ-Child design subscales. Future studies should evaluate how the AQ-C performs in population screening.