Objective: To explore adolescents' knowledge of and beliefs about dietary supplements, including herbs, and over-the-counter (OTC) medications. Methods: Eighteen focus groups with 81 adolescents in Monroe County, New York, explored teens' familiarity with and beliefs about CAM, specifically dietary supplements. We asked about general health beliefs and opinions of OTC medications to provide a framework for understanding how dietary supplements are conceptualized. Groups were conducted with suburban adolescents, urban minority adolescents, adolescents with chronic illness, (asthma, eating disorders, and diabetes), and patients of complementary/alternative practitioners ("CAM practitioners"). Transcripts were analyzed for themes relating to prevention ("staying healthy") and treatment of illness ("getting better"); direct quotations are used to illustrate adolescents' views. Results: Most adolescents are familiar with "herbal medicine," "herbal remedies," or "nutritional supplements," and are able to name specific products or complementary/alternative medicine (CAM) therapies; however, many are unfamiliar with the term "alternative medicine." Adolescents are more familiar with remedies or CAM therapies commonly used by people from their own cultural or ethnic background. Older suburban females and those with chronic illnesses are more familiar with herbs and supplements than other adolescents. Most supplement use is conceptually linked with treating illness rather than with preventive care. Conclusions: Most adolescents are familiar with culturally based herbal products and nutritional supplements, used for treatment of illnesses, and not for preventive care. Providers and researchers should consider chronic illness status and culture/family tradition, and clarify terms, when asking adolescents about self-care, OTCs, or CAM.