In this study we investigate the role of linguistic knowledge, fluency and meta-cognitive knowledge in Dutch reading comprehension of monolingual and bilingual adolescent academic low achievers in the Netherlands. Results show that these components are substantially associated with reading comprehension. However, their role appears to be different for the monolingual and bilingual low achievers. There are interactions between knowledge and fluency components with membership of the monolingual or bilingual group of low achievers, indicating that knowledge is more important in explaining reading comprehension of bilinguals, whereas fluency is more important in explaining the monolinguals' reading comprehension. Explanations of this difference between monolingual and bilingual low achievers are discussed.