Marín made his debut for Costa Rica in a June 1993 friendly match against Panama and earned a total of 128 caps, scoring 5 goals. He represented his country in 41 FIFA World Cup qualification matches and played in all 3 games during both the 2002 and 2006 FIFA World Cups. He also played at the 1997, 1999, 2001 and 2003 UNCAF Nations Cups as well as at the 1993,1998, 2002 and 2003 CONCACAF Gold Cups and the 2001 and 2004 Copa Américas. He also was a non-playing squad member at the 1997 Copa América.