Several studies in Spanish and other languages have shown that, in a lexical decision task, children are more likely to accept pseudowords with a known morphological structure as words as compared to non-morphological pseudowords. Morphology also facilitates visual word recognition of actual words in children with reading difficulties. In the present study, we explored the role of morphology, frequency and reading proficiency (measured by school grade) in visual word recognition. Typically developing readers of Spanish from 2nd, 4th and 6th grades performed a lexical decision task in which the morphological complexity and the frequency of the words were factorially manipulated. Our results showed that morphology benefited the accuracy of visual word recognition for low frequency words only. We conclude that decomposition in morphemes occurs in Spanish only for less frequent words. These results in Spanish support models that posit the decomposition of morphologically complex words in the orthographic lexicon.