To examine the possible persistence of phonological selectional constraints on young children's lexical choices, the words attempted in the conversational speech of a longitudinal sample of 12 normally-developing preschoolers from age 2;0 to 5;0 were scored for syllabic length, presence of consonant clusters, and distribution of constituent phonemes. Except at the youngest ages, few developmental changes in target word characteristics were seen, and the observed differences were largely accounted for by syntactic, lexical, and pragmatic factors. The results suggest that selectional constraints persist only briefly in the course of language acquisition.