The goal of this study was to examine the relation of morphological skills with reading fluency in 2nd grade Greek-speaking children and if phonological awareness and vocabulary mediate their relation. The sample consisted of 105 2nd grade Greek-speaking students (46 males; Mage = 7.83 years, SD = 3.31). Morphological awareness was assessed with four tasks, examining inflectional and derivational morphology both at an epilinguistic and metalinguistic level. Reading fluency was assessed with oral and silent measures. Results of path analyses indicated that inflectional and derivational morphology contributed to reading fluency through multiple pathways, controlling for the effect of Rapid Automatized Naming. Phonological awareness fully mediated the relation of inflectional and derivational morphology with text reading fluency. Vocabulary partially mediated the relation of inflectional and derivational morphology with silent reading fluency. Furthermore, derivational morphology directly affected silent reading fluency. Overall, the relation of morphological awareness with reading fluency appeared to be dynamic and varied depending on the morphological awareness skill and measure of reading fluency. Regarding the mediating role of phonological awareness and vocabulary, the results showed that children in lower elementary grades in a transparent orthography with a rich morphological system used morphological skills as activators to existing phonological and semantic skills in supporting reading fluency processes.