In an opaque orthography like English, phonological coding errors are a prominent feature of dyslexia. In a transparent orthography like Spanish, reading difficulties are characterized by slower reading speed rather than reduced accuracy. In previous research, the reading speed deficit was revealed by asking children to read lists of words. However, speed in list reading sums the time required to prepare an utterance, reaction time (RT), with the time required to say it, response duration (RD). Thus, the dyslexic speed deficit in transparent orthographies could be driven by slow RTs, by slow RDs, or both. The distinction is especially important if developmental readers rely on phonological coding to achieve lexical access because the whole word would have to be encoded before it could be identified. However, while the factors that affect reading RT have been extensively investigated, no attention has been paid to RD. We studied the performance of typically developing and dyslexic Spanish children in an oral reading task. We analysed the impact of word frequency and length on reading accuracy, RT, and RD. We found that accuracy, RT, and RD were affected by word frequency and length for both control and dyslexic readers. We also observed interactions between effects of reader group--dyslexic, typically developing (TD) younger or TD older readers--and effects of lexicality, frequency, and word length. Our results show that children are capable of reading aloud using lexical and sub-lexical coding processes in a transparent orthography.