This research assesses the effectiveness of the Brazilian public healthsystem and of private insurance in Brazil in providing financial protectionin health care. The determinants of catastrophic health expendituresare estimated by probit regressions with Heckman selection adjustmentcontrolling for health-care need. Findings show that the public systemprovides a significant reduction (47%); in the probability of a householdhaving catastrophic health expenditures, and that private insurancemakes such expenditures more likely by 36%. Recommendations includeimprovements in the quantity, accessibility, quality and reliability of publicproviders, more appropriate provision of drugs by the public system andtighter regulation of private insurance.