This study investigated whether the effect of exposure to code-switching on bilingual children's language performance varied depending on verbal working memory (WM). A large sample of school-aged Spanish-English bilingual children (N = 174, Mage = 7.78) was recruited, and children were administered language measures in English and Spanish. The frequency with which the children were exposed to code-switching was gathered through parent report. For children with high verbal WM, greater exposure to code-switching was associated with higher levels of language ability. In contrast, for children with lower verbal WM, greater exposure to code-switching was associated with lower levels of language ability. These findings indicate that children's cognitive processing capacity dictates whether exposure to code-switching facilitates or hinders language skills.