The study examined whether individual differences in the quality of phonological representations, measured by a categorical perception task (CP), are related with the use of phonological information in a lexical decision pseudohomophone task. In addition, the lexical frequency of the stimuli was manipulated. The sample consisted of Spanish-speaking normal reading adults. When high frequency stimuli were used, CP explained a significant proportion of the variance observed in the pseudohomophone effect. This result supports the idea that, even in normal reading adults, the use of phonological information during lexical access depends on the quality of their phonological representation. (Contains 1 table and 2 figures.)