To enhance understanding about the relationship between human immunodeficiency virus (HIV) infection and intravenous drug use, this article proposes extending the goals, means, and scope of ethnopharmacology to community based drug abuse research. Data for this article were collected through the National AIDS Demonstration Research (NADR) project in Houston, Texas. The data consist of participant observations and in-depth life history interviews with intravenous drug users (IVDUs). This article reports examples of IVDUs' activities and talk, such as “frosting,”“tweeking,” and “feening,” mind-set suggestion, descriptions of drug aesthetic preference, and others. These examples are used to illustrate the usefulness of a sociologically informed ethnopharmacology for investigating the HIV epidemic among IVDUs. Suggestions are made for further applications of ethnopharmacology to research on HIV transmission and IV drug use.