Changes in mood, affect, and personality may herald the onset of neurologic disturbances and may precede alterations in intellect and other cognitive operations. Reliance on traditional methods of assessment, especially in the elderly, will often produce misleading results and fail to measure critical constructs such as inappropriateness, indifference, and pragnosia. Evaluation of mood in elderly and cognitively impaired subjects is complicated by the high frequency of physical symptoms in these patients that also occur in depression and may inflate rating scale scores. Newer instruments tend to avoid items reflecting physical illness and utilize a caregiver or significant other as a rater. More research is required to develop better instruments for this population, but useful tools are becoming available for the practitioner and the researcher. From the findings reviewed above, we believe that a careful evaluation of mood, affect, and personality should be standard practice in the neuropsychological evaluation of any older adult as brain-behavior relationships are being explored. These data should stand beside data from the cognitive domains, such as attention, language, visuospatial abilities, and motor performance. Simple reliance on more traditional personality/affective measures developed for other populations (for example, psychiatric patients) is no longer sufficient, and a state-of-the-art examination calls for novel and recently devised instruments which measure constructs relevant to neuropsychological syndromes. Such an approach, we believe, will yield greater sensitivity in the early stages of incipient conditions and aid in detecting neuropsychological sequelae that may not appear in the cognitive domain.