Background: This study aimed to compare symptoms of autism spectrum disorder (ASD) in children according to attention-deficit/hyperactivity disorder (ADHD) subtypes and children without ADHD. Method: The Schedule for Affective Disorders and Schizophrenia for School-Age Children--Present and Lifetime Version (K-SADS-PL), the Social Responsiveness Scale (SRS), the Childhood Behavior Checklist (CBCL), and the ADHD Rating Scale (ADHD-RS) were used to evaluate the children. Results: ASD symptoms were significantly higher in all ADHD subtypes. After controlling for age, gender, and CBCL social withdrawal score, the difference in ASD symptoms between the 3 ADHD subtypes was not significant. Conclusions: Children with ADHD, regardless of subtype, had a similar risk of ASD symptoms.