1 January – Portugal joins ten other European nations in officially adopting the euro currency. With euro banknotes and coins not set to be introduced until 2002, the escudo remains the sole physical currency nationwide at an exchange rate of one euro to 200.48 escudo.[1]
6 May – An agreement between the Portuguese and Indonesian governments over the future of East Timor is signed by Foreign Minister Jaime Gama and his Indonesian counterpart Ali Alatas. The agreement allows East Timor, a former Portuguese colony occupied by Indonesia in 1975, to hold a referendum on whether to become an independent nation or remain an Indonesian province. Kofi Annan, the Secretary-General of the United Nations, hails the outcome as "a historic moment".[3]
13 June – European Parliament election: The Socialist Party wins the highest number of votes and seats to maintain its position as the largest Portuguese party in the European Parliament. Turnout rises by almost 5% to 40.4%, with Portugal one of just four countries across the European Union to see increased participation compared to the last elections in 1994.[6]
18 July – A preliminary parliamentary report examining the death of Prime Minister Francisco Sa Carneiro in a 1980 plane crash is leaked, in which it is suggested that the incident, originally blamed on pilot error and technical issues, was the result of a bomb explosion co-ordinated by the right-wing group Commandos for the Defence of Western Civilisation.[8]
10 October – Legislative election: The governing Socialist Party led by Prime Minister António Guterres wins the highest number of seats in the Assembly, but fails to secure an overall majority after winning exactly half of the 230 seats available. With 44.4% of the vote, the Party achieves its highest vote share in an Assembly election since the Carnation Revolution. The centre-right Social Democratic Party led by José Manuel Barroso finishes as the largest opposition party with 81 seats and 32.6% of the vote. Turnout falls to 61.9%, the lowest recorded since Portugal's return to democracy in 1974.[10]
11 December – Thirty-five people are killed when a SATA Air Açores-operated plane crashes while en route between Ponta Delgada and Horta in the Azores.[12] Pilot error is later blamed as the main factor for the incident in a report published in 2001.[13]
^"Os 20 momentos marcantes da história do Bloco" [The 20 landmark moments in the history of the Bloc]. Diário de Notícias (in Portuguese). Lusa News Agency. 27 February 2019. Retrieved 5 September 2021.
^Corkill, David (2000). "Portugal's October 1999 election: Not quite a foregone conclusion". West European Politics. 23 (3): 201–206. doi:10.1080/01402380008425392.
^Barros, Mário (9 June 1999). "O homem que marcou o hóquei". Público (in Portuguese). Archived from the original on 11 October 2021. Retrieved 12 October 2021.