The Bureau of Labor Statistics' American Time Use Survey (ATUS), launched in 2003, offers the first comprehensive look at how individuals spend their time. Health services researchers can use it to study time spent on a variety of health-related activities. We explain the survey's structure and provide an overview of the health-related activities reported by 34,693 respondents in 2003-2004.For the ATUS, computer-assisted phone interviewers ask respondents age 15 or older to report their activities during the day before the call (their "designated day"), including where they were and who was with them. Activities are assigned 6-digit codes, grouped into 17 major categories. Associated waiting and travel time have separate codes. Certain household types are oversampled to ensure reliable estimates.In 2003-2004, 11.3% of American adults reported spending time (mean, 108 minutes) on activities related to health on their designated day. Some 5.6% reported personal health self-care (86 minutes); 3.4% reported medical and care services (123 minutes); and about 1% each reported activities related to the health of household children, household adults, and nonhousehold adults (78-115 minutes). The prevalence of health-care related activities rose with age. Sports, exercise, and recreation were reported by 17.6% of respondents (114 minutes), with men more likely than women to report these activities.The ATUS, a new publicly available resource, allows researchers to explore factors that influence time devoted to health-related activities, and the relationships among them and other activities, in a nationally representative sample.