BACKGROUND: Many public health recommendations and clinical guidelines emphasize the importance of healthy lifestyles. Recent epidemiologic studies demonstrate that following a healthy lifestyle has substantial health benefits. The objectives of this study were to report on the prevalence of healthy lifestyle characteristics (HLCs) and to generate a single indicator of a healthy lifestyle. METHODS: National data for the year 2000 were obtained from the Behavioral Risk Factor Surveillance System, which consists of annual, statewide, random digit–dialed household telephone surveys. We defined the following 4 HLCs: nonsmoking, healthy weight (body mass index [calculated as weight in kilograms divided by the square of height in meters] of 18.5–25.0), consuming 5 or more fruits and vegetables per day, and regular physical activity (≥30 minutes for ≥5 times per week). The 4 HLCs were summed to create a healthy lifestyle index (range, 0–4), and the pattern of following all 4 HLCs was defined as a single healthy lifestyle indicator. We report prevalences of each HLC and the indicator by major demographic subgroups. RESULTS: By using data from more than 153 000 adults, the prevalence (95% confidence interval) of the individual HLCs was as follows: nonsmoking, 76.0% (75.6%–76.4%); healthy weight, 40.1% (39.7%–40.5%); 5 fruits and vegetables per day, 23.3% (22.9%–23.7%); and regular physical activity, 22.2% (21.8%–22.6%). The overall prevalence of the healthy lifestyle indicator (ie, having all 4 HLCs) was only 3.0% (95% confidence interval, 2.8%–3.2%), with little variation among subgroups (range, 0.8%–5.7%). CONCLUSION: These data illustrate that a healthy lifestyle—defined as a combination of 4 HLCs—was undertaken by very few adults in the United States, and that no subgroup followed this combination to a level remotely consistent with clinical or public health recommendations.