We investigated parent reports of use of special education and support services, use of evidence-based practices (EBPs), use of past and current complementary and alternative medicine (CAM) treatments, non-use of CAM treatments, willingness, and unwillingness to use CAM treatments, reasons for use and non-use of CAM treatments, and perceptions of EBPs and CAM treatments in their children's functioning. We collected data from a total of 166 parents of children with autism spectrum disorder (ASD) through a web-based survey. 94% of the parents reported lifetime use of at least one CAM treatment. Parents weighed on a wide variety of factors in decision-making. CAM treatments use was positively associated with parental educational level, length of time since ASD diagnosis, and child's ASD severity.