Psycholinguistic experiments conducted with the picture-word interference paradigm are typically preceded by a phase during which participants learn the words they will have to produce in the experiment. In Experiment 1, the pictures (e.g., a frog) were to be named and were presented with a categorically related (e.g., "cat") or unrelated distracter (e.g., "pen"). In the related condition responses were slower relative to the unrelated condition for the participants who had gone through the learning phase. In contrast, participants who had not been previously familiarized with the materials showed facilitation. In Experiment 2 one group of participants, as usual, learned to produce the targets upon presentation of the corresponding pictures (e.g., a frog). The other group learned to produce the same targets upon presentation of unrelated pictures (e.g., a clock). They showed very similar semantic effects. The implications of the findings in the study of word production are discussed.