Martínez made his debut for Honduras in a November 1999 friendly match against Guatemala and has earned a total of 38 caps, scoring 13 goals. He has represented his country in 4 FIFA World Cup qualification matches and played at the 2000 Summer Olympics. He also played at the 2001, 2003 and 2007 UNCAF Nations Cups as well as at the 2000, 2003s and 2007 CONCACAF Gold Cup.