Non-adherence to medical regimens is a critical threat to HIV-infected individuals. Persons living with HIV/AIDS must adhere to their outpatient medical appointments to benefit from continually improving HIV care regimens. The primary purpose of the present study was to identify individual and psychosocial characteristics associated with HIV-related medical appointment non-attendance. One hundred seventy eight adult participants attending the Outpatient Adult HIV/AIDS Immunology Clinic at Jackson Memorial Hospital (JMH) in Miami, Florida participated in the study. Scheduled and missed appointments obtained retrospectively over a 12-month period indicated that medical appointment non-attendance was a significant problem. Overall, 27.9% of scheduled appointments were missed during the study period. Young age and limited family support were predictors of non-attendance. These findings support those of others and highlight targeted intervention efforts to reduce appointment non-attendance among persons living with HIV/AIDS.