Few studies analyze the effects of health insurance on inpatient care in low income countries. This paper provides an empirical assessment of the influence of Vietnam's health insurance schemes on both hospital admission and the length of stay (LOS) using the Vietnam National Health Survey 2001–2002 and an appropriate count data regression model. Our findings suggest that the influence of health insurance on hospital admission and the LOS varies across insurance schemes. The compulsory insurance scheme and the insurance scheme for the poor increase the expected LOS by factors of 1.18 and 1.39, respectively, while the voluntary insurance scheme has minimal effect on the expected LOS. Insurance also increases the likelihood of hospital admission far more for compulsory members than for members of the other two insurance schemes. The positive influence of insurance on hospital admission and the LOS also varies across income quintiles, regions and types of health facilities. While the compulsory and voluntary schemes increase the likelihood of hospital admission more for lower and middle income individuals, the influence of the compulsory scheme on the expected LOS is more pronounced for patients in the middle income groups. The influence of insurance on the LOS is also found to be stronger in the North than in the South and stronger for patients admitted to provincial hospitals rather than district hospitals.