Recent studies have documented dramatic decreases in opportunistic infections, hospitalizations, and mortality among HIV-infected persons, owing primarily to the advent of highly active antiretroviral medications. Unfortunately, not all segments of the population living with HIV benefit equally from treatment. In San Francisco, only about 30% of the HIV-infected urban poor take combination highly active antiretroviral medications, as compared with 88% of HIV-infected gay men. Practitioners who care for the urban poor are reluctant to prescribe these medications, fearing inadequate or inconsistent adherence to the complicated medical regimen. Persons typically must take 2 to 15 pills at a time, 2 to 3 times a day. Some of the medications require refrigeration, which may not be available to the homeless poor. Most homeless persons do not have food available to them on a consistent schedule. Therefore, they may have difficulty adhering to instructions to take medications only on an empty stomach or with food. Lack of a safe place to store medications may be an issue for some. In addition, many urban poor live with drug, alcohol, or mental health problems, which can interfere with taking medications as prescribed. Inconsistent adherence to medication regimens has serious consequences. Patients do not benefit fully from treatments, and they will become resistant to the medications in their regimen as well as to other medications in the same classes as those in their regimen. Development of resistance has implications for the broader public health, because inadvertent transmission of multidrug-resistant strains of HIV has been demonstrated. Concern that the urban poor will not adhere to highly active antiretroviral medication regimens has led to debate on the role of clinicians and public health officials in determining who can comply with these regimens. Rather than define the characteristics that would predict adherence to these regimens, the San Francisco Department of Public Health created a program to support adherence among those who may have the greatest difficulty complying with complicated highly active antiretroviral medication regimens. The program, dubbed the Action Point Adherence Project, was conceived through a community planning process in preparation for a city-wide summit on HIV/AIDS that took place in January 1998. Action Point is funded by the city and the county of San Francisco. Now in its 10th month, the program continues to show promising evidence of improving clients' biological and social indicators.