Modern developmental psychology tends to draw a positive, resource-based picture of human aging. We will however focus on more difficult aspects of personality in old age which are of psychiatric relevance: the persistence of cluster A and C personality disorders, antisocial personality in the elderly; the interaction of personality and a detection of mild cognitive impairment (MCI); personality features as risk or protective factors or early signs of Alzheimer's dementia; changes of personality in Parkinson's disease and frontotemporal dementia. We will briefly mention recent neuroimaging studies which appear to suggest a functional neuroanatomy of personality. A quote from Cicero's cato major, de senectute indicates that some of his perceptions regarding classic personality characteristics of the elderly can be recognized in our patients and can be prevented or treated with modern interventions.