In Costa Rica lists political parties in this country. Costa Rica used to have a two-party system, which meant that there were two dominant political parties, with extreme difficulty for anybody to achieve electoral success under the banner of any other party. After the 2002 elections and the strong showing a few third parties had, the two-party system is considered to be in its last breath. There are several important political parties now, and the 2006 elections will eventually decide how the Costa Rican political landscape will look like.
The Social Christian Unity Party (Partido de Unidad Social Cristiana) is a political party in Costa Rica. At the last legislative elections, 3 February 2002, the party won 29.8 % of the popular vote and 19 out of 57 seats. At the presidential elections of the same date, its candidate, Abel Pacheco de la Espriella won 38.6 % of the vote. He was elected in a runoff election with 58.0 %.
PUSC considers itself a Christian Democratic Party and as such is a member of the Christian Democrat and People's Parties International.
The National Liberation Party (Spanish: Partido Liberación Nacional; commonly abbreviated as PLN) is a political party in Costa Rica. The PLN was founded by José Figueres Ferrer in 1948, following the end of the Costa Rican Civil War. It soon became one of the most important in the country. In 2002, for the first time in history, it lost its second consecutive election. The party won only 27.1 % of the popular vote and 17 out of 57 seats. At the presidential elections of the same date, its candidate, Rolando Araya Monge won 31.0 % (the worst showing ever for the party) of the vote and was defeated in the run off election by Abel Pacheco.
Some of the most dynamic and popular leaders that have presided over the country have come from the PLN. Among them are National Civil War Hero José Figueres Ferrer and Nobel Peace Prize winner Óscar Arias Sánchez.
The party is a member of the Socialist International.
The Citizen's Action Party (Spanish: Partido Acción Ciudadana; commonly abbreviated as PAC) is a political party in Costa Rica. Its plaform is based on encouraging citizen participation and involvement in politics. One of its guiding ideals is to fight against corruption, arguing that it is one of the main causes of subdevelopment and voter apathy.
It was founded in December 2000 and startled the Costa Rican political arena with a very strong showing in the 2002 general elections. In the presidential vote, party founder and candidate Ottón Solís was able to secure 26% of the votes – an unprecedented amount for a third party in Costa Rica – and force a runoff between the two traditional parties, the PLN and the PUSC.
The party won 21.9 % of the popular vote and 14 out of 57 seats in the Legislative Assembly, making it the third strongest political force in the legislature. A few months later, however, after a series of internal disputes, six of the party's 14 deputies resigned from the party, leaving PAC with only eight seats.
The Partido Movimiento Libertario ("Libertarian Movement Party") is a libertarian political party in Costa Rica. It was founded in May 1994 and, since then, has enjoyed a number of victories. It succeeded in getting attorney Otto Guevara, a Harvard graduate, elected to the Legislative Assembly in its first campaign in 1998.
In 2002, Guevara ran for president (unsuccessfully, 1.7 % of the vote), and the party won at the legislative elections won 9.3 % of the popular vote and 6 out of 57 seats. A few weeks after taking office, one Congressman left the party and became independent, leaving PML with five seats. The PML is an observer of the Liberal International, so therefore it is also listed as a liberal party.
After the national assemblies of June 25 and August 13, 2005, there was an internal upheaval at the party. The secretary general, treasurer, and many others of a strong ideological libertarian bent have left the party, to be replaced by what Otto Guevara termed "moderates".
It has been argued by the ideological libertarians currently leaving the party, those he classified as radicals in the press, that most of the people entering the party and vying for congressmen posts are not actually libertarians at all, given they include supporters of items such as employment quotas by sex.
On September 10, 2005, the Movimiento Libertario's assembly voted by overwhelming majority to accept government money for political campaign purposes, something that had so far been officially characterized by the party as "immoral".
The Costa Rican Renovation Party (Partido Renovación Costariccense) is a Christian political party in Costa Rica. At the last legislative elections, 3 february 2002, the party won 3.6 % of the popular vote and 1 out of 57 seats. At the presidential elections of the same date, its candidate, Justo Orozco Alvarez won 1.1 % of the vote.
The Democratic Force (Fuerza Democrática) is a political party in Costa Rica. At the last legislative elections, 3 february 2002, the party won 2.0 % of the popular vote and no seats.
The National Integration Party (Partido Integración Nacional) is a political party in Costa Rica. At the last legislative elections, 3 february 2002, the party won 1.7 % of the popular vote and no seats.
Government 
