This article examines socio-economic determinants and inequality of health care utilization in Ecuador. Despite health reform efforts in Latin America, drastic socio-economic inequalities persist across the region, including Ecuador. Almost a third of Ecuador's population lack regular access to health services, while more than two-thirds have no health insurance and insufficient resources to pay for health care services. Using Andersen's model of health care utilization behaviour, relevant variables were selected from the 2004 National Demographic and Maternal & Child Health Survey (ENDEMAIN) household survey. Four outcomes were assessed: use of preventive services, number of curative visits, hospitalization, and use of antiparasitic medicines. Adjusting for various predisposing, enabling and need factors, a significant negative relationship was found between household economic status (as measured by assets and consumption quintiles) and utilization of preventive and curative services. The same was true for use of antiparasitic medicines. Further, indigenous ethnicity was found to be a significant negative predictor of health care utilization, regardless of economic status. These socio-economic inequalities in the use of health care services suggest the need for health care reform in Ecuador to address these issues more systematically. It is necessary for public health authorities to move forward on a reform that will expand coverage, particularly to indigenous and low- and middle-income households.