Word age-of-acquisition (AoA) affects reading. The mapping hypothesis predicts AoA effects when input-output mappings are arbitrary. In Spanish, the orthography-to-phonology mappings required for word naming are consistent; therefore, no AoA effects are expected. Nevertheless, AoA effects have been found, motivating the present investigation of how AoA can affect reading in Spanish. Four experiments were run to examine reading with a factorial design manipulating AoA and frequency. In Experiments 1 and 2 (immediate and speeded naming), only word frequency affected word naming. In Experiment 3 (lexical decision), both AoA and frequency affected word recognition. In Experiment 4 (immediate naming with highly imageable items), both frequency and AoA affected naming. The results suggest that highly imageable items induce a larger reliance on semantics in reading aloud. Such reliance causes faster naming of earlier acquired words because the corresponding concepts have richer visual and sensory features acquired mainly through direct sensory experience.