HIV/AIDS is concentrated among the inner-city poor and poverty may directly interfere with HIV treatment. This study examined food insufficiency in relation to HIV-related health and treatment. A sample of 344 men and women living with HIV/AIDS in Atlanta, Georgia completed measures of food security, health, and HIV disease progression and treatment. HIV treatment adherence was monitored using unannounced pill counts. Results showed that half of people living with HIV/AIDS in this study lacked sufficient food, and food insufficiency was associated with multiple indicators of poor health, including higher HIV viral loads, lower CD4 cell counts, and poorer treatment adherence. Adjusted analyses showed that food insufficiency predicted HIV treatment non-adherence over and above years of education, employment status, income, housing, depression, social support, and non-alcohol substance use. Hunger and food insecurity are prevalent among people living with HIV/AIDS, and food insufficiency is closely related to multiple HIV-related health indicators, particularly medication adherence. Interventions that provide consistent and sustained meals to people living with HIV/AIDS are urgently needed.