Resistance to interference from irrelevant auditory stimuli undergoes development throughout childhood. To test whether semantic processes account for age-related changes in a Stroop-like picture-word interference effect, children (3-to 12-year-olds) and adults named pictures while listening to words varying in terms of semantic relatedness to the pictures and response set membership. In Experiments 1 and 2, with animal and clothing pictures, the interference effect observed in children, but not in adults, depended on the distractors' status as members of the response set. In Experiment 3, with unrelated pictures, adults, but not children, showed greater interference for trials with distractors in the response set. These results indicate developmental changes in picture-word interference involving the establishment of a response set in working memory.