Feeding and mealtime behavior problems are an area of concern for those with autism spectrum disorders (ASD) because of their impact on daily functioning, as well as the potential for causing severe medical conditions (e.g., poor nutrition, choking, aspiration) and even death. Due to the importance of this topic for proper diagnosis and treatment planning, a better understanding of these behaviors in persons with ASD and intellectual disabilities (ID) is important. Participants in this study were 60 adults with ASD and ID (group 1) or ID only (group 2). Individuals with ASD and ID evinced more behaviorally-based feeding problems, such as food selectivity and refusal related difficulties relative to their peers with ID alone as assessed with the Screening Tool of fEeding Problems (STEP). Those with ID only had more feeding skill difficulties than persons with ASD and ID. Overall, the ASD and ID group evinced more, and more severe feeding and mealtime problems. Implications of these data are discussed.