Objective: The authors assessed the psychometric properties of the Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form (Q-LES-QSF) in adults with ADHD. Method: One hundred fifty ADHD and 134 non-ADHD adults from a case-control study and 173 adults randomized to placebo or methylphenidate were assessed with the Q-LES-QSF and the Social Adjustment Scale (SAS). Response to change was estimated by comparing change in Q-LES-QSF scores in responders and nonresponders in our randomized clinical trial. Results: Internal consistency of the Q-LES-QSF items was 0.88, and the correlation between the Q-LES-QSF total score and the SAS total T score was 0.72 in adults with ADHD. ADHD cases had statistically significantly poorer scores on the Q-LES-QSF than controls (76.5 [plus or minus] 10.9 vs. 59.2 [plus or minus] 17.3, p greater than 0.001), whereas ADHD responders showed Q-LES-QSF improvement compared to nonresponders (76.1 [plus or minus] 12.0 versus 67.9 [plus or minus] 14.5, p greater than 0.001). Conclusion: These results support the validity of the Q-LES-QSF as a measure of quality of life in adults with ADHD. (Contains 1 table and 1 figure.)