Demand-side financing (DSF) is used in the less-developed countries of the world to improve access to healthcare and to encourage market supply. Under DSF, households receive vouchers that can be used to pay for healthcare services. This study evaluated the effects of a universal DSF on maternal healthcare service utilization in Bangladesh. A household survey was conducted in and around the voucher scheme area one year after the initiation of the project. Women who gave birth within a year prior to the survey were interviewed. The utilization rates of maternal health services were found to be higher for all socioeconomic groups in the project area than in the comparison areas. Voucher recipients in the project area were 3.6 times more likely to be assisted by skilled health personnel during delivery, 2.5 times more likely to deliver the baby in a health facility, 2.8 times more likely to receive postnatal care (PNC), 2.0 times more likely to get antenatal care (ANC) services and 1.5 times more likely to seek treatment for obstetric complications than pregnant women not in the program. The degree of socioeconomic inequality in maternal health service utilization was also lower in the project area than in the comparison area. The use of vouchers evidenced much stronger demand-increasing effects on the poor. Poor voucher recipients were 4.3 times more likely to deliver in a health facility and two times more likely to use skilled health personnel at delivery than the non-poor recipients. Contrary to the inverse equity hypothesis, the voucher scheme reduced inequality even in the short run. Despite these improvements, socioeconomic disparity in the use of maternal health services has remained pro-rich, implying that demand-side financing alone will be insufficient to achieve the Millennium Development Goal for maternal health. A comprehensive system-wide approach, including supply-side strengthening, will be needed to adequately address maternal health concerns in poor developing countries