Four ethnographic field stations described in this article were established through three research projects studying drug use behaviors in New York City. Field log entries are used to describe the search for a field site and actual conduct of the research, including sampling and recruitment, use of key informants, and protection against violence and theft. The ethnographic field site facilitates the collection of longitudinal data from reasonably large samples, provides stability and continuity to researcher-subject relationships, and enhances the project's legitimacy in the neighborhood. Some of the weaknesses associated with the field station include the high cost, potential for inertia, and deterioration of the quality of subjects over time. 5 references