Objective: The aim was to examine associations of age and gender with ADHD subtypes and subsequently to examine associations of age, gender, and subtypes with comorbid psychiatric disorders. Method: Odds ratios were calculated and logistic regression performed using information from a clinical sample of 155 ADHD adults referred to a Danish specialized ADHD unit from 2010 to 2011. Results: A majority of men (65%) was found in the sample. Most patients were subtyped ADHD combined (78%), followed by ADHD inattentive (18%), and ADHD hyperactive-impulsive (4%). No significant differences were found in gender and age across subtypes. Current comorbid disorders were found in 57% of the ADHD patients. Significantly more comorbidity was found in the ADHD combined type and in patients ≥25 years. Significantly more men had substance use disorders and significantly more women had personality disorders. Conclusion: When assessing adult ADHD patients’ age, gender, subtype, and related comorbid symptom profiles should be taken into account. (J. of Att. Dis. XXXX; XX(X) XX-XX)