Antofagasta, Osorno, Melipilla, and Deportes Concepción were relegated last season to the Primera B.
Universidad de Chile qualified to the 2010 Copa Libertadores Second Stage.
Updated as of games played on December 9, 2009.Source: Relegation for this season will be determined by an aggregate table of the Classification Stages of both the Apertura and Clausura tournaments.
Curicó Unido, by finishing 16th in the relegation table, played against San Luis, the loser of the 2009 Primera B championship playoff.
The team who obtains the most point after two legs will stay or be promoted to the Primera División.