Martínez made his debut for Guatemala as a late substitute in an October 2002 friendly match against Jamaica and went on to collect a total of 51 caps, scoring no goals. He has represented his country in 11 FIFA World Cup qualification matches and at the 2003, 2005 and 2007 CONCACAF Gold Cup Finals as well as at the 2003, 2005 and 2007 UNCAF Cup tournaments.