The study examines the influence of bilingual experience, age and verbal working memory (WM) on the comprehension of passive voice by 116 typically developing (TD) and 65 autistic children aged 3 to 13, who were tested in their societal languages, German or French. Some children were mainly exposed to the societal language while some children were also exposed to other languages. We adopt a continuous approach to bilingual experience and operationalize it as a balance of cumulative exposure, measured through entropy scores. We found that the comprehension of passive voice improved with age in both groups, and higher verbal WM predicted better performance in autistic but not TD children. Although autistic children were less accurate than TD children, bilingual experience did not contribute to the differences between the two groups. These findings suggest that bilingualism has no detrimental effect on the comprehension of complex syntactic structures in autistic children.