General elections were held in Costa Rica on 5 February 2006. In the presidential election, Óscar Arias of the National Liberation Party, a former president and Nobel Peace Prize laureate, won over Ottón Solís of the Citizens' Action Party and twelve other minor-party candidates.

Although Arias had been expected to win comfortably, the race proved much closer than anticipated. Preliminary results, with 88.45% of ballots counted, showed Arias leading with 40.51% of the vote, compared to 40.29% for Solís, a margin of only 3,250 votes. Owing to the narrow difference, the Supreme Electoral Court ordered a manual recount of all ballots and postponed the official declaration of the winner until the process was completed. The recount, concluded approximately two weeks later, confirmed Arias's victory.

In the parliamentary election, the National Liberation Party emerged as the largest party in the Legislative Assembly for the first time since 1994. It won the highest number of seats, although it fell four seats short of an outright majority.

There were fourteen candidates running for the presidency in the 2006 elections. However, only a few rose in the polls above the error margin.

Óscar Arias, the candidate of the National Liberation Party (PLN), was widely regarded as the frontrunner throughout the campaign. Arias had previously served as President of Costa Rica from 1986 to 1990.

Internationally, he was best known for his role in promoting the Esquipulas Peace Agreement, which contributed to the resolution of armed conflicts in Central America during the 1980s, particularly in Nicaragua, El Salvador, and Guatemala. In recognition of these efforts, he was awarded the Nobel Peace Prize in 1987. He later established the Arias Foundation for Peace and Human Progress, an organization dedicated to peacebuilding, demilitarization, conflict resolution, and the promotion of human rights Through this group Arias helped to settle conflicts throughout Latin America, participating in the process to demilitarize Haiti and Panama.

Arias made the fight against poverty and corruption the headlining issues of his campaign. During public appearances he promised to provide scholarships to poor families so their children could stay in school and not have to work (a promise he fulfilled on his first day in office), and spoke about the urgency of signing the Central American Free Trade Agreement in order to create high-paying jobs for Costa Rica's youth.

With the pre-election opinion polls favoring Óscar Arias, he did not foresee such stiff competition from his closest rival Ottón Solís. At first count, there was a difference of only 0.4% (Óscar Arias = 40.6% vs Ottón Solís = 40.2%), or about 3,200 votes. Large numbers of voters supporting candidates other than Óscar Arias and Ottón Solís chose to cast their ballot for Ottón Solís at the last minute, with the objective of keeping Óscar Arias from winning the elections.