Drawing on a longitudinal data collection of six children (three hearing, three deaf) learning Dutch and Sign Language of the Netherlands (NGT) in deaf families, this paper explores the amount and types of simultaneous mixing (code-blending) of signed and spoken language elements in the children’s linguistic input and output. The hearing children receive far more code-blending in their input than the deaf children; they also produce more than the deaf children. The types of code-blending also differ between the two groups of children. The factors that determine these differences appear to be the language ability of the children, the input and the language choice. Finally an analysis of the classes of signs/words shows that more nouns than verbs are code-blended and more verbs than adjectives/adverbs, pronouns, or question words. Linguistic factors and the input seem to play a part here.