These elections were called after the decision of President Jorge Sampaio on 30 November 2004 to dissolve the Parliament as an answer to the political instability caused by the government led by Pedro Santana Lopes (PSD) in coalition with the PP.

The campaign started officially on 6 February and the major topics were the problematic state of the country's finances, unemployment, abortion and even José Sócrates's alleged homosexuality.

[1][2] Headed by Sócrates, the centre-left Socialist Party (PS) won the election with a landslide victory, winning in 19 of the 22 electoral constituencies, including in districts such as Viseu and Bragança that historically voted for the right.

Deep disagreements and disputes within the Social Democratic Party began to derail the government led by Pedro Santana Lopes.

[9] Pedro Santana Lopes, by then Mayor of Lisbon, was the sole candidate for the leadership[10] and his name was overwhelmingly confirmed in a National Party Council meeting on 1 July 2004.

[14] José Sócrates was elected by a landslide[15] and the results were the following: In the fall of 2004, PCP leader Carlos Carvalhas decided to step down from the party's leadership after 12 years in the post.