OBJECTIVES: To estimate the economic burden of unintended pregnancy in the perspective of public payer and the impact of UP on related public health measures in Brazil. METHODS: A decision-analysis cost model was constructed based on pregnancy rates, probabilities and costs of pregnancy and neonatal outcomes (miscarriage, induced abortion, and live birth) in Brazil. The model took account of both maternal and child outcomes, and accounted for healthcare costs related with preterm birth, neonatal admission, cerebral palsy, neonatal and maternal mortality. All costs are reported as Real$ (Brazilian currency). RESULTS: In Brazil there were 1.8 million unintended pregnancies in 2010. Those unintended pregnancies resulted in 159,151 miscarriages, 48,769 induced abortions, and 1.58 million live births. It was estimated there were 312 maternal deaths. The number of infant deaths within the 12-months following birth was estimated at 32,864. The total healthcare costs to public payer attributed to unintended pregnancies are estimated to be R$4.1 billion in one year of which R$4.07 billion (99.2%) attributed to births and resulting complications and R$32 million (0.8%) was attributed to miscarriage. The average cost per UP was R$2,293. CONCLUSIONS: Unintended pregnancies impose substantial burden on the Brazilian society in term of healthcare costs, infant and maternal morbidity and mortality. Reduction in UPs will not only generate substantial cost-savings, but also improve public health profile of the country. Public policymakers should allocate budget on cost-effective pregnancy prevention interventions to address this issue.