A recent meta-analysis reported a prevalence rate of 2.2% for older adults (> 50 years) with symptom levels indicating an ADHD diagnosis, but a rate of only 0.23% for the proportion with a clinical diagnosis. Thus, ADHD symptoms are relatively frequent among older adults, but few have a formal diagnosis. The few studies of older adults that exist suggest that ADHD in older adulthood is associated with the same cognitive deficits, comorbid disorders and impairments in daily life functioning (e.g. poor working memory, depression, psychosomatic comorbidity and poor quality of life) as found in younger adults with this disorder. Evidence based treatments for children and younger adults (pharmacotherapy, psychoeducation and group-based therapy) are most likely also effective treatment options for older adults, but research is lacking. In summary, increased knowledge is needed to allow access to diagnostic assessment and treatment for older adults with clinically significant ADHD symptom levels.