ABSTRACT. Objective: To identify Attention Deficit Hyperactivity disorder (ADHD) in older adults, a validated screener is needed. This study evaluates the reliability and criterion validity of an ADHD screener for younger adults on its usefulness in a population-based sample of older adults. Methods: Data were collected as a side study in the Longitudinal Aging Study Amsterdam. In a two-phase design the validity of the screener was tested against a structured diagnostic interview (DIVA 2.0). In Phase 1, 1,494 respondents (60-94 years) were assessed with the ADHD screener. In Phase 2, 231 respondents participated in the diagnostic interview. Results: Internal consistency (Cronbach's α) and reliability (ICC) of the screener were 0.71 and 0.56, respectively. The area under the curve was 0.82. The optimal cut-point was found at 2 (sensitivity: 0.80; specificity: 0.77; PPV: 0.13; NPV: 0.99). Conclusion: Despite its low ICC, the ADHD screener may serve as a useful contribution to measure ADHD in the older population.