Children with autism spectrum disorders (ASD) are often referred to art therapy. To investigate what works in art therapy with children with ASD, the tacit knowledge of 8 experienced art therapists was explored through interviews. Promising components were arranged into the Context and Outcomes of Art Therapy (COAT) model. According to the respondents, art therapy with children with ASD contributes to becoming more flexible and expressive, more relaxed, and more able to talk about their problems in the therapeutic setting as well as in their home situation. Considering the evidence in this study, further empirical research into the process and outcomes of art therapy with children with ASD is strongly recommended.