Objective: This study investigates attributional styles and psychosocial functioning of men and women with ADHD identified in adulthood to inform practice issues. Method: One hundred and eighty adults participate: 52 females with ADHD, 37 males with ADHD, 51 female controls, and 40 male controls are administered questionnaires broadly assessing attributional style and psychosocial functioning. Results: The ADHD groups report more depression and anxiety, greater childhood dissatisfaction, a more external locus of control and lower self-esteem, and being more likely to be classified with a maladaptive attributional style than controls. No specific gender differences are noted in the ADHD groups, although a few overall gender differences emerge, with males reporting lower self-esteem, a more external locus of control, and more dissatisfaction in childhood than females. Conclusion: Consistent with other research, ADHD participants, regardless of gender, are struggling significantly with psychosocial functioning. (Contains 3 tables and 2 figures.)