This study examined the prevalence and correlates of use of different types of complementary and alternative medicine (CAM) among a sample of children with suspected or recently diagnosed autism. The authors’ review of 284 charts of children seen at the Regional Autism Center of The Children’s Hospital of Philadelphia, Pennsylvania, found that more than 30% of children were using some CAM, and that 9% were using potentially harmful CAM. Having an additional diagnosis was protective against CAM use and being Latino was associated with CAM use. Having seen a prior provider regarding the child’s health condition was predictive of potentially harmful CAM use. Further research is required on cultural differences in treatment decisions about CAM, as well as the reasons for the association between the use of prior providers and CAM. The high prevalence of CAM use among a recently diagnosed sample indicates that clinicians should discuss CAM early in the assessment process.