Documented variability in augmentative and alternative communication (AAC) intervention outcomes makes it difficult for clinicians to select systems most likely to be effective for individual children with autism spectrum disorder (ASD). The aim of this study was to identify child-related factors associated with AAC intervention outcomes through a systematic review of the research literature. A search was conducted of peer-reviewed research articles in which AAC intervention outcomes and associated factors were reported for children with ASD. The search yielded 965 titles and abstracts, of which seven articles relating to six studies met criteria for inclusion. In total, 18 factors were examined, of which nine were assessed as predictors (e.g., cognition, ASD severity, language use), three as moderators (e.g., joint attention, object exploration), and six as mediators (e.g., frequency of therapy, communication partner knowledge). Child characteristics associated with communication outcomes were pre-intervention cognition, severity of ASD, verbal imitation, vocabulary comprehension, object use, joint attention, language use, and two multi-dimensional measures of communication competence. This study suggests emerging evidence for predictors, but less is known about what factors moderate and mediate response to AAC interventions.