Abstract In the last few years, in several parts of the world, under extreme weather conditions, several catastrophic fires have taken place. These fires are called mega-fires. They are not just large fires but extreme events in their behavior, difficulty to control and impacts. Portugal historically has little experience with mega-fires, but recent fire events exacerbated by climate change and landscape management has changed this situation. In the year 2003, the worst and largest wildfires were ever recorded in the Algarve region and in the central region of Portugal. However, this paper focuses on the Algarve region, using primary (i.e. questionnaires, interviews, satellite images, and fieldwork) and secondary data (i.e. Portuguese wildfire database, central and local governments’ fire damages reports). Using wildfire ecological and socio-economic impacts as an important criterion to classify an event as a mega-fire, this paper conclude that two mega-fires occurred in 2003 in the Algarve Region. Taking into account the weakness in Portuguese wildfire impacts reporting process, it is proposed a checklist of categories of damages and losses to support future data acquisition. Considering that mega-fires are a new reality in Portugal, this paper shows that increasing suppression capabilities in terms of means, readiness and effectiveness are important to avoid small fires to become mega-fires in days of critical fire danger. Nevertheless, facing the impossibility of changing the extreme weather conditions, given the complexity and uncertainty surrounding mega-fires occurrence and severity, the main challenge is to improve wildfire risk reduction instead of focusing only on fire suppression. This paper proposes a framework which conceptualizes fire impacts as a result of interaction between fire behavior, vulnerability and suppression capabilities. It can be used for promoting wildfire prevention and mitigation. It is urgent to enhance prevention measures in order to change fire behavior and reduce vulnerability of ecosystems and societies, as well as to increase the engagement of communities in wildfire risk management.