BackgroundThe aim of this study was to investigate autism spectrum disorder (ASD) clinical practice patterns of Korean medicine doctors (KMDs) through questionnaire survey.MethodsQuestionnaires on Korean medicine (KM) treatment for ASD were distributed to 255 KMDs on December 5, 2016. The KMDs were psychiatrists, pediatricians, or general practitioners, who treated patients with ASD. The questionnaire covered items on treatment methods, aims of treatment, KM syndrome differentiation, diagnostic tools, and sociodemographic characteristics. Frequency analysis was conducted to describe the participants and their practices.ResultsA total 22.4% KMDs (n = 57/255) completed the questionnaires and 54 KMDs (21.2%) matched the inclusion criteria. The KMDs utilized herbal medicine (27.3%), body acupuncture (17.6%), scalp acupuncture (10.7%), moxibustion (6.4%), and Korean medical psychotherapy (5.9%) to treat ASD. The most commonly prescribed herbal medicine was Yukmijihwang-tang. Forty-eight (88.9%) KMDs responded that they used KM syndrome differentiation. ‘Organ system, Qi, Blood, Yin, Yang, Fluid and Humor diagnosis’ was most frequently used for syndrome differentiation. ASD was mainly diagnosed based on the fourth edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM-IV) and DSM-5.ConclusionsThe present study demonstrated the current status of KMDs’ diagnosis and treatment of ASD. In future clinical trials and clinical practice guidelines, these findings will provide meaningful information on the actual practice patterns of KMDs.Electronic supplementary materialThe online version of this article (10.1186/s12906-018-2162-4) contains supplementary material, which is available to authorized users.