The Socceroos have slipped six places to number 48 on the latest world rankings issued by governing body FIFA.
The only match Australia have played since last month's rankings is the 2-1 defeat to Uruguay at Sydney's Telstra Stadium.
Uruguay have also slipped, dropping seven spots to number 30 despite the victory over Australia.
The Socceroos will have an opportunity to move back up the rankings when they contest the Asian Cup for the first time, commencing in July.
Australian opponents in the Asian Cup could include number 40 Japan, the highest ranked Asian team.
Former World Cup winners France have moved up two places to number 2 behind current holders Italy.
The Italians are on 1653 points, with France - thanks mainly to two consecutive wins in the Euro 2008 qualifying campaign - moving up to second at the expense of Brazil, who moved one place down to third.
Germany moved one place up to fourth - their best FIFA ranking in four years - at the expense of Argentina, who drop two places to fifth.
FIFA Rankings
1. Italy
2. France
3. Brazil
4. Germany
5. Argentina
6. Portugal
7. Spain
8. England
9. Netherlands
10. Czech Republic
48. Australia
