Equity in health care financing is recognised as a main goal in health policy. It implies that payments should be linked to capacity to pay and that households should be protected against catastrophic health expenditure (CHE). The risk of CHE is inversely related to the share of out-of-pocket payments (OOP) in total health expenditure. In Portugal, OOP represented 26% of total health expenditure in 2010 [one of the highest among Organisation for Economic Co-operation and Development (OECD) countries]. This study aims to identify the proportion of households with CHE in Portugal and the household factors associated with this outcome. Additionally, progressivity indices are calculated for OOP and private health insurance. Data were taken from the Portuguese Household Budget Survey 2010/2011. The prevalence of CHE is 2.1%, which is high for a developed country with a universal National Health Service. The main factor associated with CHE is the presence of at least one elderly person in households (when the risk quadruples). Payments are particularly regressive for medicines. Regarding the results by regions, the Kakwani index for total OOP is larger (negative) for the Centre and lower, not significant, for the Azores. Payments for voluntary health insurance are progressive.