This narrative review provides an updated overview of the effects of bilingualism on language and cognition of children with neurodevelopmental disorders. Our multi-pronged search yielded literature conducted with populations with developmental language disorder, autism spectrum disorder and attentional disorders, hearing impairment and other neurodevelopmental disorders and conditions. Although much of the focus remains on developmental language disorder and autism spectrum disorder, research interests are slowly growing to fill in the gaps of how bilingualism affects other populations with differential patterns of development. Our review shows that a conclusive understanding of this relationship is hindered by the assessment types (i.e., not validated for bilinguals) and practices (e.g., confounds, languages assessed) involved in the evaluation of bilingual children. Areas such as acquired pediatric disorders remain understudied. Defining, measuring, and reporting bilingualism as multi-dimensional, persists as an obstacle to cross-comparison between children with different disorders. Recommendations for further investigations in this area are provided.