Background: Eastern European health system indicators (e.g., number of health workers and care coverage) suggest well-resourced maternity care systems, but maternal health outcomes compare poorly with those in Western Europe. Often, poor maternal health outcomes are linked to inequities in accessing adequate maternal care. This study investigates access-related barriers (availability, appropriateness, affordability, approachability, and acceptability) to maternity care in Romania, Bulgaria, and Moldova. Methods: This cross-country study (n = 7345) is based on an online survey where women who received maternity care and gave birth in 2015–2018 in Bulgaria (n = 4951), Romania (n = 2018), and Moldova (n = 376) provided information on their experiences with the care received. We used regression analysis to identify factors associated with accessing maternity care across the three countries. Results: Results show high rates of cesarean births (CB) and a low number of antenatal and postnatal care visits. Informal payments and use of personal connections are common practices. Formal and informal out-of-pocket payments create a financial burden for women with health complications. Women who had health complications, those who gave birth by cesarean, and women who gave birth in a public facility and had fewer antenatal check-ups, were more likely to describe facing access-related barriers. Conclusions: This study identifies several barriers to high-quality maternity care in Romania, Bulgaria and Moldova. More attention should be paid to the appropriateness of care provided to women with complicated pregnancies, to those who have CBs, to women who give birth in public facilities, and to those who receive fewer antenatal care visits.