BACKGROUND: Antenatal Care (ANC), use of skilled delivery attendants and postnatal care (PNC) services are key maternal health services that can significantly reduce maternal mortality. Understanding the factors that affect service utilization helps to design appropriate strategies and policies towards improvement of service utilization and thereby reduce maternal mortality. The objective of this study was to identify factors that affect utilization of maternal health services in Ethiopia. METHODS: Data were drawn from the 2011 Ethiopia Demographic and Health Survey. The dependent variables were use of ANC, skilled delivery attendants and PNC services. The independent variables were categorized as socio-cultural, perceived needs and accessibility related factors. Data analysis was done using SPSS for windows version 20.0. Bivariate and multivariate logistic regression models were used in the analysis. RESULTS: Thirty four percent of women had ANC visits, 11.7% used skilled delivery attendants and 9.7% of women had a postnatal health checkup. Education of women, place of residence, ethnicity, parity, women's autonomy and household wealth had a significant association with the use of maternal health services. Women who completed higher education were more likely to use ANC (AOR = 3.8, 95% CI = 1.8-7.8), skilled delivery attendants (AOR = 3.4, 95% CI = 1.9-6.2) and PNC (AOR = 3.2, 95% CI = 2.0-5.2). Women from urban areas use ANC (AOR = 2.3, 95% CI = 1.9-2.9), skilled delivery attendants (AOR = 4.9, 95% CI = 3.8-6.3) and PNC services (AOR = 2.6, 95% CI = 2.0-3.4) more than women from rural areas. Women who have had ANC visits during the index pregnancy were more likely to subsequently use skilled delivery attendants (AOR = 1.3, 95% CI = 1.1-1.7) and PNC (AOR = 3.4, 95% CI = 2.8-4.1). Utilization of ANC, delivery and PNC services is more among more autonomous women than those whose spending is controlled by other people. CONCLUSION: Maternal health service utilization in Ethiopia is very low. Socio-demographic and accessibility related factors are major determinants of service utilization. There is a high inequality in service utilization among women with differences in education, household wealth, autonomy and residence. ANC is an important entry point for subsequent use of delivery and PNC services. Strategies that aim improving maternal health service utilization should target improvement of education, economic status and empowerment of women.