• Objectives: To document the prevalence of use of herbal products among adults in a large metropolitan area and to examine issues surrounding such use. • Subjects and Methods: Of people aged 18 years and older residing in the Minneapolis/St Paul, Minn, metropolitan area, 752 were randomly selected from Minnesota Department of Public Safety Driver and Vehicle Service Division data tapes. Between June and August 1999, surveys were mailed to determine use of any herb and use of 13 specific herbs. Rationale for use, perceived efficacy, and source of product information were assessed for each of the specific herbs. • Results: Of the initial 752 persons, 580 were eligible, and 376 returned a completed survey, resulting in a response rate of 65 %. When asked whether they had used an herb during the past 12 months, 230 respondents (61.2%) reported that they had. Prevalence of use of specific herbs ranged from 30.9% for ginseng to 3.0% for milk thistle. The most commonly reported reasons for using herbs varied by the type of herb, although for 5 of the herbs, the most frequently mentioned reason was to promote general health/well-being. For 11 of the 13 herbs, less than 60% of those who used the herb rated it as effective or very effective. Family, friends, and written materials were the leading sources of product information among those taking 9 of the 13 specific herbs. • Conclusions: Herbs are used frequently to treat or prevent an array of health conditions. At present, people who use herbal products appear to rely predominantly on family and friends for information.