Regardless of their limited evidence and potential adverse effects, use of complementary and alternative medicine is common in children with autism spectrum disorder. Nevertheless, data on complementary and alternative medicine use in children with autism spectrum disorder in Germany are lacking. Therefore, a questionnaire survey on the use of complementary and alternative medicine was distributed to parents of children with autism spectrum disorder from three academic autism spectrum disorder outpatient clinics in Germany. Of 211 respondents, 46% stated that their child currently used or had ever used some form of complementary and alternative medicine in their life. The complementary and alternative medicine modalities most frequently used were manipulative and body-based methods (e.g. craniosacral therapy). And 18% of caregivers expressed willingness to try complementary and alternative medicine treatments for their child with autism spectrum disorder in the future, with mind–body interventions predominating. Health professionals should be aware of the considerable complementary and alternative medicine use prevalence among children with autism spectrum disorder and offer parents information about its effectiveness and potential side effects.