Despite some well-documented differences, normal aging and Alzheimer's disease (AD) share a number of common neuropathological and neuropsychological features. Many of the reported differences are largely quantitative in nature and there is often overlap between the respective distributions of these populations. To assess the issue of overlap and distinguishing features in memory functions between these groups, and to minimize aging effects per se, samples of older individuals in good health (ages 75-95 yr) and younger patients in the early stages of AD (age < 75 yr) were selected to be similar in global cognitive functioning. Despite comparable language and visuospatial scores, these preliminary results suggest important qualitative differences in episodic memory functions between these conditions, even when "low-functioning" or "at-risk" controls are compared with early AD patients. These findings furthermore highlight some of the challenges in defining "normality" among the oldest segment of our population.