Children, four, six, eight, and twelve years old, and adults participated in a study of judgments of syllable similarity. Subjects listened to a disyllabic nonsense unit (the standard) followed by two comparison stimuli; they were then asked to choose the comparison stimulus "most like" the standard. Changes between the comparison stimuli and the standard stimuli were systematically varied. Analyses of results indicated that syllables which shared the largest number of phonemes with the standard were judged most similar and that this phenomenon was age related. Eight- and twelve-year-olds' ranking of syllables was significantly similar to adult rankings. The responses of four- and six-year-olds were inconsistent, and the number of choices for each syllable type did not differ from chance expectations. Results are discussed in the context of a syllable approach to reading instruction. (Author/AA)