In the United States, monitoring the HIV/AIDS epidemic among the incarcerated population is done by (a) conducting a census of persons in prisons and jails reported to be infected with HIV or diagnosed with AIDS, (b) seroprevalence surveys in selected correctional facilities, and (c) population-based HIV/AIDS case surveillance by state health departments. We describe methods for HIV/AIDS case surveillance in correctional settings and present data from the HIV/AIDS Reporting System (HARS) and the Supplement to HIV and AIDS Surveillance (SHAS) to describe the demographic, behavioral, and clinical characteristics of HIV-infected persons who were incarcerated at the time of diagnosis. HARS data showed a higher proportion of females and a lower proportion of injection drug users for incarcerated persons diagnosed with HIV (not AIDS) compared to those initially diagnosed with AIDS. The SHAS data showed a high prevalence of injection drug use, crack use, alcohol abuse, and exchanging sex for money or drugs. Together, HARS and SHAS collect fairly comprehensive information of risk behaviors from persons with HIV infection and AIDS. Advances in HIV prevention and care for the incarcerated community will require an accurate and timely description of the magnitude of the HIV epidemic in correctional settings. These data are needed to guide programmatic efforts to reduce HIV transmission in prisons and jails and in the general community upon release and ensure needed risk reduction and health care services for incarcerated persons.