Purpose Developing country workers mainly face important challenges when examining equality in health services utilization among the population and identifying influential factors. The purpose of this paper us to: understand health service use among households with different socio-economic status in Isfahan province; and to investigate probable inequality determinants in service utilization. Design/methodology/approach Almost 1,040 households living in Isfahan province participated in this cross-sectional study in 2013. Data were collected by a questionnaire with three sections: demographic characteristics; socio-economic status; and health services utilization. The concentration index was applied to measure inequality. Analysts used STATA 11. Findings Economic status, educational level, insurance coverage and household gender were the most influential factors on health services utilization. Those with a high socio-economic level were more likely to demand and use such services; although self-medication patterns showed an opposite trend. Practical implications Female-headed families face with more difficulties in access to basic human needs including health. Supportive policies are needed to meet their demands. Originality/value The authors used principle component analysis to assess households' economic situation, which reduced the variables into a single index.