PROBLEM: High-risk behaviors and lack of preventive care are associated with higher rates of morbidity and mortality in the United States. Without continued monitoring of these factors, state health departments would have difficulty tracking and evaluating progress toward Healthy People 2010 and their own state objectives. Monitoring chronic disease-related behaviors is also key to developing targeted education and intervention programs at the national, state, and local levels to improve the health of the public. REPORTING PERIOD COVERED: Data collected in 2001 are compared with data from 1991 and 2000, and progress toward Healthy People 2010 targets is assessed. DESCRIPTION OF SYSTEM: The Behavioral Risk Factor Surveillance System (BRFSS) is an ongoing, state-based, telephone survey of persons aged > or =18 years. State health departments collect the data in collaboration with CDC. In 2001, participants in data collection included all 50 states, the District of Columbia, Guam, the U.S. Virgin Islands, and the Commonwealth of Puerto Rico. BRFSS data are used to track the prevalence of chronic disease-related characteristics and monitor progress toward national health objectives related to 1) decreasing high-risk behaviors, 2) increasing awareness of medical conditions, and 3) increasing use of preventive health services. For certain national objectives, BRFSS is the only source of data. RESULTS: BRFSS data indicate changes in certain high-risk behaviors from 1991 to 2001. Among the findings are substantial increases in the prevalence of obesity among adults aged > or =20 years. Among states, prevalence of persons classified as obese in 2001 ranged from 15.5% in Colorado to 27.1% in Mississippi. From 1991 to 2001, the median prevalence for all participating states and territories increased from 12.9% to 21.6%. In 1991, no state had an obesity prevalence of > or =20%; in 2001, 37 states had a prevalence of > or =20%. Percentage increases in prevalence of obesity, from 1991 to 2001, ranged from 24.9% in the District of Columbia to 140.2% in New Mexico. In 2001, substantial variations also existed among states and territories regarding prevalence of other high-risk behaviors and awareness of medical conditions. Ranges included, for no leisure-time physical activity, 16.5% (Utah) to 49.2% (Puerto Rico); cigarette smoking, 9.6% (Virgin Islands) to 31.2% (Guam); binge drinking, 6.8% (Tennessee) to 25.7% (Wisconsin); heavy drinking, 2.5% (Tennessee) to 8.7% (Wisconsin); persons ever told they had diabetes, 4% (Alaska) to 9.8% (Puerto Rico); persons ever told they had high blood pressure, 20% (New Mexico) to 32.5% (West Virginia); and persons ever told they had high blood cholesterol, 24.8% (New Mexico) to 37.7% (West Virginia). Substantial variations also existed among states regarding prevalence of using preventive health services. Ranges included, for persons aged > or =50 years ever screened for colorectal cancer by use of sigmoidoscopy or colonoscopy, 30.5% (Virgin Islands) to 62% (Minnesota); persons aged > or =65 years who received an influenza vaccination in the past year, 36.8% (Puerto Rico) to 79% (Hawaii); persons aged > or =65 years who ever received a pneumococcal vaccination, 24.1% (Puerto Rico) to 70.9% (Oregon). In 2001, 13 states, Guam, and the U.S. Virgin Islands used the women's health module. Ranges included, for women aged > or =18 years who had a Papanicolaou (Pap) smear test in the past 3 years, 79.8% (Virgin Islands) to 89.6% (Wisconsin); women aged > or =40 years who ever had a mammogram, 71.9% (Virgin Islands) to 93% (Rhode Island); and women aged > or =40 years who had a mammogram in the past 2 years, 57.2% (Virgin Islands) to 85.1% (Rhode Island). BRFSS data in 2001 also indicated variations by sex, race or ethnicity, and age group. Greater percentages of men than women reported cigarette smoking, binge drinking, heavy drinking, and were classified as overweight; greater percentages of women reported no leisure-time physical activity. Among racial or ethnic groups, greater percentages of black non-Hispanics than other groups reported being told by a health professional they had high blood pressure and diabetes, and were classified as obese; greater percentages of white non-Hispanics than other groups reported being told they had high cholesterol. Among age groups, greater percentages of persons aged 18-24 years than those in older groups reported smoking cigarettes, binge drinking and heavy drinking; greater percentages of persons in older age groups than younger age groups reported being told they had diabetes, high blood pressure, and high blood cholesterol. Also, comparison of 2001 BRFSS data with 12 targets from Healthy People 2010 indicates that, in 2001, no state had met the targets for obesity, cigarette smoking, binge drinking, receiving a fecal occult blood test within the past 2 years, receiving annual influenza vaccinations, receiving pneumococcal vaccinations, and receiving Pap tests. Certain states had already met targets for no leisure-time activity, receiving a sigmoidoscopy or colonoscopy, having blood cholesterol checked within the past 5 years, and receiving a mammogram within the past 2 years. INTERPRETATION: BRFSS data in this report indicate that despite certain improvements, persons in a high proportion of U.S. states and territories continue to engage in high-risk behaviors and do not report making sufficient use of preventive health practices. Substantial variations (i.e., by state, sex, age group, and race/ethnicity) in prevalence of behaviors, awareness of medical conditions, and use of preventive services indicate a continued need to monitor these factors at state and local levels and assess progress toward reducing morbidity and mortality. PUBLIC HEALTH ACTIONS: BRFSS data can be used to guide public health actions at local, state, and national levels. For certain states, BRFSS is the only reliable source of chronic-disease-related, risk-behavioral data. BRFSS data enable states to design, implement, evaluate, and monitor health-promotion strategies, targeting specific high-risk behaviors among populations experiencing high burdens of disease. BRFSS data continue to be key sources for assessing progress toward both national Healthy People 2010 objectives and state health objectives.