The first legs will be played on November 15 and the return on November 19.
The two have met 15 times with Sweden winning six and Portugal three, but Sweden have not beaten Portugal in seven matches since 1984. They met twice in the qualifiers for the 2010 World Cup and drew 0-0 on both occasions.
"Sweden are a team which will give us two very complicated matches, two evenly balanced ones. Although they have one of the best forwards in the world, Sweden are strong collectively," Portugal coach Paulo Bento said.
The last meeting between France and Ukraine ended in a 2-0 win for France after thunder and lightning caused their Euro 2012 match in Donetsk to be suspended last year. France, who were unseeded in the draw and at 21st are world ranked one place below Ukraine, boast an unbeaten record against the East Europeans with four wins and three games drawn.
"Ukraine are a team who do not concede a lot of goals, but it's good we are playing the second leg at home," said France coach Didier Deschamps who was relieved to have avoided Portugal in the draw.
France finished second behind world champions Spain in European Group I while Ukraine were runners-up to England in Group H.
Greece, who finished behind Bosnia on goal difference in Group G, first met Romania in 1930 and will be wary of a team who beat them 3-1 in a friendly the last time they met in late 2011. Iceland are the lowest ranked team in the playoffs at 46.
Their only previous meetings with Croatia came in 2005 when Croatia won at home and 3-1 away in the qualifying stages for the 2006 World Cup in Germany.
The draw (first-named teams in the list below play their home legs first):
Portugal v Sweden
Ukraine v France
Greece v Romania
Iceland v Croatia