The contribution of linguistic skills to reading has been reported in different languages; however, this contribution varies according to the specific features of each language. Arabic is characterized by diglossia, i.e. the existence of two distinct varieties: Spoken Arabic (SpA) and Standard Arabic (StA). This study examined the extent to which linguistic components (phonemic awareness, vocabulary, morphological and syntactic knowledge) and orthographic knowledge of kindergartners (N = 261) predict future reading skills, i.e. word reading accuracy, fluency, and reading comprehension in the first year of elementary school (first grade). In addition, the relevant contributions of SpA and StA to reading skills were tested. The results revealed that while phonemic awareness, syntactic and orthographic knowledge significantly predicted almost all reading skills, morphological knowledge and vocabulary predicted only reading comprehension. In addition, hierarchical regression showed that the general index of StA linguistic measures predicted all reading measures, after controlling for orthographic knowledge and SpA linguistic measures. The results are discussed in relation to the critical role of StA in reading acquisition despite the difficulties of Arabic-speaking kindergartners in processing language in StA compared to SpA. The study emphasizes the influence of oral and written linguistic skills on reading acquisition in Arabic.