Common knowledge supports the belief that occasional napping is a ubiquitous human behavior, yet epidemiological reports on napping vary in methodological quality and tend to focus on specific sub-groups of the lifespan. A notable weakness in the napping literature is a lack of data on African Americans, and an ongoing question is whether daytime napping has a negative impact on nighttime sleep. Given these limitations in the literature another study seemed warranted. The present study uses a high quality epidemiological data set collected via random digit dialing that includes 50 men and women in each age decade ranging from 20 to 80+, and a substantial proportion of African Americans, to answer the following questions. What is typical napping Behavior? Are there ethnic or gender differences in napping behavior? How does napping behavior change across the adult lifespan? Do persons with insomnia nap more than normal sleepers? Is there a relation between daytime napping and quality of nighttime sleep? The results suggested that a majority of people nap and naps are more frequent in African Americans and persons with insomnia, with older adults napping more frequently, but taking briefer naps. A significant relation was also found between daytime napping and nighttime sleep with daytime napping relating to increased onset latency and decreased total sleep time on the following night but with daytime napping also relating to increased wake time in the middle of the night and decreased total sleep time on the previous night.