Objective
To assess the out-of-pocket (OOP) payments for health-care services of HIV/AIDS patients, and identify associated factors in Vietnam.

Methods
Cross-sectional multisite survey of 1016 HIV/AIDS patients attending 7 hospitals and health centres in Ha Noi, Hai Phong and Ho Chi Minh City in 2012.

Results
HIV/AIDS patients used inpatient and outpatient care on average 5.1 times (95% CI = 4.7–5.4) besides ART services. Inpatient care cost US$ 461 on average and outpatient care US$ 50. Mean annual health-care expenditure for HIV/AIDS patients was US$ 188 (95% CI = 148–229). 35.1% of households (95% CI = 32.2–38.1) experienced catastrophic health expenditure; 73.3% (95% CI = 70.6–76.1) of households would be affected if ART were not subsidised. Being a patient at a provincial clinic, male sex, unstable employment, being in the poorest income quintile, a CD4 count of <200 cells/mL and not yet receiving ART increased the likelihood of catastrophic medical expense.