PHP was founded to address the AIDS epidemic for injection drug users, sex workers, transgendered individuals, homeless persons, and individuals recently released from incarceration in New York City. PHP’s mission is to reduce the spread of HIV infection among drug users by reducing risk behaviors, minimizing the harm associated with drug use, and breaking down barriers to HIV prevention, health care, and other critical services. The agency opened as a small drop-in center offering support groups, outreach, and counseling for drug users seeking respite from the streets. Within a year, PHP offered a full range of harm reduction services, including syringe exchange and supportive services. Since then, the agency has steadily expanded its range of services, establishing an international reputation for its nonjudgmental service delivery model, high-quality harm reduction programs, and mission-driven services that focus on its clients’ need for confidentiality, and respect.