An election of MEP representing Portugal constituency for the 1999–2004 term of the European Parliament was held on 13 June.

The party, headed by its founder and former President of the Republic and Prime Minister Mário Soares, scored a convincing victory over the Social Democrats.

The PS increased its share of vote more than 8 percent and won 2 more seats compared with 1994.

The Communist/Green alliance won more than 10 percent of the votes, a drop of around 1 point, and lost one seat but was able to reclaim the title of 3rd largest party.

Deputies are elected in a single constituency, corresponding to the entire national territory.