Objective: Children with ADHD-combined type (ADHD-C), disruptive mood dysregulation disorder (DMDD), and healthy controls (HC) were compared with respect to the sociodemographic features, psychiatric comorbidities, behavioral patterns, and family functioning. Method: Research groups were identified using the Schedule for Affective Disorders and Schizophrenia for School-Age Children–Present and Lifetime Version (K-SADS-PL). Conners’ Rating Scale–Revised Long Form, Wechsler Intelligence Scale for Children–Revised (WISC-R) test, Sociodemographic Questionnaire, and Family Assessment Device (FAD) were administered to research groups. Results: DMDD group’s rate of psychiatric comorbidity was higher than the ADHD-C group’s rate. In most of the subscales of Conners, DMDD group’s average scores were higher than the other groups’ scores. In "Communication," "Affective Responsiveness" subscales of FAD, DMDD group’s average scores were higher than the ADHD-C group’s scores. In "Affective Involvement," "General Functioning" subscales of FAD, DMDD group’s average scores were higher than the other groups’ scores. Conclusion: Children with DMDD were distinguished from children with ADHD-C by their higher comorbidity rate, more impaired behavioral patterns, and family functioning.