Autism is more prevalent among persons with Restrictive type eating disorders (R-ED) compared to the general population and is associated with poorer outcomes across treatment modalities. Knowledge is sparse with regard to whether poorer outcomes are also associated with Family-based treatment (FBT), which is recommended as the first choice of treatment for young persons (YPs) with R-ED. This case series compares outcome between groups with and without autism in a large consecutive series of YPs with R-ED treated with FBT.