Objective: Social cognitive functions in adults with ADHD were investigated in a virtual social exchange game. Method: The sample consisted of 40 participants (20 adult ADHD participants, 20 healthy controls). Participants played a multiround trust game with virtual trustees who differed in regard to fairness and presence of emotional facial cues. Results: Investments were higher in ADHD participants than in healthy participants except for partners who played fair with constant neutral expressions. ADHD patients did not adapt their behavior to the fairness of the trustee. In the presence of emotional facial cues, ADHD and healthy participants transferred more monetary units to happy rather than angry-looking trustees. Differences in investment behavior were not linked to deficits in emotion-recognition abilities or cognitive dysfunctions. Conclusion: Alterations in interaction behavior and in the formation of a general attitude toward social partners could be shown in adults with ADHD.