Objectives To increase insight into the effect of attention-deficit/ hyperactivity disorder (ADHD) on health in general in older adults. Design Two-phase sampling side-study. Setting Longitudinal Aging Study Amsterdam (LASA). Participants Two hundred twenty-three randomly selected LASA respondents. Measurements Information was collected during home visits on physical health, medication use, and lifestyle characteristics in Phase 1 and on ADHD diagnosis in Phase 2. The associations between independant variables and ADHD were examined with linear and logistic regression analyses. Results The adjusted regression estimates of the linear regression analysis showed that the number of ADHD symptoms was positively associated with the presence of chronic nonspecific lung diseases (CNSLD) (B = 2.58, P =.02), cardiovascular diseases (B = 2.18, P =.02), and number of chronic diseases (B = 0.69, P =.04) and negatively associated with self-perceived health (B = -2.83, P =.002). Lifestyle is not a mediator of the association between ADHD and physical health. Conclusion Attention-deficit/hyperactivity disorder in older adults was associated with chronic physical illness and poorer self-perceived health. Contrary to expectations, there were no associations between symptoms of ADHD and lifestyle variables. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.