We studied the cost and affordability of 'free' maternity services at government facilities in Dhaka, Bangladesh, to assess whether economic factors may contribute to low utilization. We conducted a questionnaire survey and in-depth interviews among 220 post-partum mothers and their husbands, selected from four government maternity facilities (three referral hospitals and one Mother and Child Health hospital) in Dhaka. Mothers with serious complications were excluded. Information was collected on the costs of maternity care, household income, the sources of finance used to cover the costs, and the family's willingness to pay for maternity services. The mean cost for normal delivery was 1275 taka (US$31.9) and for caesarean section 4703 taka (US$117.5). Average monthly household income was 4933 taka (US$123). Twenty-one per cent of families were spending 51-100% of monthly income, and 27% of families 2-8 times their monthly income for maternity care. Overall, 51% of the families (and 74% of those having a caesarean delivery) did not have enough money to pay; of these, 79% had to borrow from a money lender or relative. Surprisingly, 72% of the families said they were willing to pay a government-levied user charge, though this was less popular among low-income families (61%). 'Free' maternity care in Bangladesh involves considerable hidden costs which may be a major contributor to low utilization of maternity services, especially among low-income groups. To increase utilization of safer motherhood services, policy-makers might consider introducing fixed user charges with clear exemption guidelines, or greater subsidies for existing services, especially caesarean section.