Objective: The aim of this study was to empirically determine subgroups of ADHD defined by specific patterns of psychopathology. Method: A clinical sample of 223 children with ADHD, aged 5 to 14 years, was examined with the Child Behavior Checklist (CBCL). In addition, comorbid psychiatric disorders, psychosocial risk factors, and socioeconomic status were assessed. Results: Cluster analysis of CBCL subscales yielded a solution with four distinct subgroups. While "externalizers" showed a high rate of comorbid oppositional defiant disorder (ODD) and conduct disorder (CD), "obsessive-compulsives" exhibited thought problems, low rates of comorbid CD, and high symptoms of inattention. "High psychiatric symptom carriers" had high rates of familial risk factors, acute life events, comorbid ODD, and CD. "Low psychiatric symptom carriers" also scored low in all other variables studied. Conclusion: Children with ADHD can be divided into four subgroups according to their CBCL-based psychopathology, and these subgroups differ in their risk factor profiles. (J. of Att. Dis. 2013; XX(X) XX-XX)