Purpose: The present study examined the nature of the effects (direct or indirect) of vocabulary, phonological and morphological awareness on early reading skills in the consistent Greek orthography by testing a unifying model of early reading development in a sample of 141 first-grade children. Method: Vocabulary, phonological and morphological awareness were assessed in the middle of grade 1, whereas word reading accuracy, word reading fluency, and reading comprehension were measured at the end of the same grade. Results: Results from structural equation modeling showed that phonological awareness directly predicted word reading accuracy, which mediated the effects of phonological awareness on reading comprehension and word reading fluency. Reading comprehension was directly supported by vocabulary, which also mediated the effect of morphological awareness on reading comprehension. Morphological awareness had an indirect effect on word reading accuracy through phonological awareness and via this distal path indirectly predicted reading comprehension and word reading fluency. Conclusion: Findings highlight the complex relations between oral language and early reading skills and suggest that, although the effects of oral language skills may differ depending on the reading outcome, all of them can significantly promote early reading development. Therefore, they should be included during reading instruction.