DescriptionAutism Spectrum Disorder (ASD) is characterized by deficits in communication. Training in vocal approximations and/or augmentative and alternative communication (AAC) modes may be required to overcome these deficits. Because it may be difficult to determine a best communication fit for each student, one solution is to assess students' preference for the different communication topographies. Several factors have been found to influence preference, including parameters of reinforcement, parameters of a response, reinforcement histories, and stimulus cues. The present investigation specifically examined the effects of reinforcement histories and associative salient stimuli on communication modality preference in two students with autism. The two modalities under investigation were vocal approximations and a speech-generating device (SGD). After acquiring labels of items with the two modalities, both participants showed an initial preference for the SGD. One participant continued to label items with the SGD, even when he did not access reinforcement for responding with that modality. For another participant, when reinforcement histories were established with the different modalities - first vocals, then the SGD - his preference shifted to match whichever modality was most recently reinforced. His preferences were unaffected by the presence of salient cues, suggesting that reinforcement histories alone may influence students' preference for different communication topographies.