As no presidential candidate received a majority of the vote, a second round was held between the top two candidates—Sebastián Piñera and Eduardo Frei Ruiz-Tagle—on Sunday 17 January 2010.

Three communist MPs were elected (Guillermo Teillier, Hugo Gutiérrez and Lautaro Carmona), while incumbent Speaker of the Chamber, Rodrigo Álvarez (UDI) was defeated by Marcela Sabat (RN).

The far-left Juntos Podemos Más pact selected former Socialist Party member Jorge Arrate as its candidate.

Frei became the single Concertación candidate by beating Gómez by a 20-point lead, cancelling the need for further regional primaries.

In the other hand the left-wing Juntos Podemos Más, that it suffered an internal division after the exit of the Humanist Party.

The largest party inside the A list was the Christian Democrats, with the leadership of Juan Carlos Latorre who was chief of the Eduardo Frei's presidential campaign.

The Alliance for Chile for the elections of 2009, began with an important step, by means of I arrive of two precandidates, one of them the senator Pablo Longueira, and the mayor of Concepción, Jacqueline van Rysselberghe, both of the Independent Democratic Union, who demonstrated his availability of postulating to this post, using the regular conduits inside the coalition, nevertheless, both rejected such an option to present only a presidential candidate, who would be Sebastián Piñera.

The above mentioned agreements were not lacking in polemic, since the Senator who postulated the alliance to preside at the above mentioned organism, Jovino Novoa, was harshly criticized for personeros of the Concert in view of his past as member of Augusto Pinochet Ugarte's military regime.

In spite of the critiques, the Alliance for Chile awarded a political victory on having presided at both chambers of the National Congress and some of the most influential commissions of the same one, which, they waited in the conglomerate opponent, he was benefiting Sebastián Piñera's candidacy.

After having integrated the list Clean Chile, Vote Happy, one was generated fail between the charter members of ChileFirst with regard to the position that would take the party opposite to the presidential and parliamentary elections of 2009.

Whereas Jorge Schaulsohn and Senator Flores supported the candidate of the Alliance for Chile Sebastián Piñera,[70] the deputy Esteban Valenzuela rejected to join with the center-right and resigned ChileFirst to endorse Marco Enríquez-Ominami's candidacy.

[75] Another poll by La Segunda found 23% thought Piñera had won the debate, followed by Arrate (21%), Enríquez-Ominami (15%) and Frei (9%).

A poll carried out by Mayor University showed Piñera had won the debate by 41%, followed by Enríquez-Ominami (22%), Arrate (19%) and Frei Ruiz-Tagle (17%).

On 20 December 2009, the Juntos Podemos Más coalition gave its support to Eduardo Frei's candidacy, after the former president agreed to include a number of policies into his government program.