The Welsh suffered an agonising 9-8 semifinal loss to France after playing more than three-quarters of the match with 14 men after captain Sam Warburton's red card. Warren Gatland's team then lost the third place playoff 21-18 to Australia.
Despite their impressive performances throughout the tournament, Wales, who began the tournament in sixth place, have dropped below Ireland and Argentina in the rankings, which are issued each week by the International Rugby Board.
The All Blacks, who beat France 8-7 to become world champions for the first time for 24 years, top the rankings ahead of Australia, France, South Africa and England, who remain in fifth place despite an unimpressive World Cup campaign in which they exited in the quarterfinals.
