The goal of this study was to examine to what extent the conditions of restricted input of L2 and SLI have an additive impact on language acquisition. Therefore, the Dutch language achievement of 6-, 7-, and 8-year-old bilingual children with SLI was compared with that of typically developing monolingual Dutch children, typically developing bilingual children, and monolingual Dutch children with SLI. Assuming that speaking a language in varying environments involves distinct subskills that can be acquired in differential patterns, the achievement of phonological, lexical, morphosyntactic and textual abilities were assessed separately. For each of these abilities, it was determined to what extent the conditions of restricted input (first vs. second language) and language deficit (typically developing vs. SLI) cause stagnation or a delay in language acquisition. Bilingual children with SLI perform at a lower level than the other groups in almost all aspects of achievement in Dutch. For language tasks related to the mental lexicon and grammar, an additional disadvantage was evidenced as a result of the combination of learning Dutch as second language and having SLI. (Contains 1 figure and 1 table.)