AbstractBilingualism has sometimes been associated with cognitive boosts, particularly in working memory (WM). However, itremains unclear whether such benefits extend to the comprehension of syntactically complex structures. We investigated thisthrough a gamified character-selection task assessing comprehension of subject-relative clauses and object-relative clauses amongmonolingual (n = 31) and bilingual (n = 28) French-speaking children, as well as monolingual(n = 45) and bilingual (n = 43) German-speaking children aged 3 to 12. We examined whethercomprehension correlated with verbal WM, measured through a nonword repetition task, and interference resolution ability, assessedthrough a Simon task and an analysis of comprehension errors. The results indicated no bilingual advantage: object-relativeclauses were more difficult than subject-relative clauses across all groups and languages. While interference-related errors —misinterpreting object-relative clauses as subject-relative clauses more frequently than vice versa — surfaced in all groups,verbal WM correlated with object-relative comprehension only in French. These findings are discussed in relation to currenttheories of bilingualism and WM in language comprehension.