This longitudinal study investigated profiles of lexical quality domains in preschool children and the extent to which profile membership predicted reading comprehension in first grade. A latent profile analysis was conducted to classify 420 preschool children on lexical quality domains, including orthography, phonology, morphosyntax, and vocabulary. Regression analysis was used to determine whether profile membership was associated with first grade outcomes across reading comprehension and its components (i.e., listening comprehension and word recognition). Results revealed five profiles of lexical quality which were predictive of all three outcomes in first grade. Children in low lexical quality profiles performed more poorly on the outcome measures than children in the higher lexical quality profiles. Additionally, profile membership did differentially predict later reading outcomes. These results suggest that lexical quality profiles are associated with reading and therefore may offer a means of early identification of children who are susceptible to future reading difficulties. (author abstract)