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Adult aging is often associated with declining efficiency of executive functions (EFs), and these changes have, in turn, been attributed to aging-related changes in the frontal lobes and in frontal systems. However, questions have been raised about the nature, validity, and specificity of these relationships. What is the operational definition of EF or, in specific studies, what operational definition was used? What measures are used to assess EF, and what is the relationship of these measures to the operational definitions? What is the relationship of these constructs to neuroanatomy? Finally, how are neural networks to be considered within this brain–behavior relationship? Our review is structured as follows. The first section highlights studies of cognitive aging, that is, experimental, theoretically motivated approaches to understanding aging-related changes in cognitive functioning. The next section emphasizes research in aging and EF from a neuropsychological standpoint with a spotlight on studies using putative tests of EF and/or frontal lobe functioning. A review of studies of EF in association with structural and/or functional imaging indices follows. In the last section, we attempt to integrate these concepts, not to postulate a new theory but to suggest a way forward in addressing the questions that have been raised. This review is selective rather than exhaustive. The focus is on normal or healthy aging and does not address issues involving alterations in EF that occur with mild cognitive impairment and the different forms of dementia.