Assessment and diagnosis of mental disorders has become standard practice in the counseling profession. In this article, the authors examine problems and solutions associated with accurate assessment and diagnosis of conduct disorder. Problems of conduct disorder assessment and diagnosis include (a) client deceitfulness, (b) parent and teacher misinformation, (c) counselor countertransference, (d) diagnostic comorbidity, and (e) confounding cultural and situational circumstances. Counselors seeking to accurately diagnose conduct disorder should adhere to basic assessment principles; use multi-method, multi-rater, multisetting approaches; closely review differential explanations and diagnoses; and regularly obtain peer consultation.