This paper examines the relationship between language dominance and the under-investigated topic of inter-sentential code-switching in Hong Kong Cantonese–English bilingual children. Longitudinal data for six children showing different dominance patterns were analysed. MLU differentials (Yip & Matthews, 2006) were adopted to measure dominance based on five criteria: methodological compatibility, typological comparability, gradient measurement, variance validity, and multifaceted compatibility. Our results showed that bilingual children produced more inter-sentential code-switching in the context of their non-dominant language and less in their dominant-language context. We account for this asymmetry in relation to mechanisms of inhibitory control (Gross & Kaushanskaya, 2015). Further, we propose that intrasentential and inter-sentential code-switching each have a different status in bilingual children’s developing grammar, underlining the methodological importance of separating the two constructs in future investigations. We also suggest that, in societies where intra-sentential code-switching is a social norm, inter-sentential code-switching could serve as signs of early bilinguals’ dominance status.