Iran has dropped four places to 51st with 574 points in the latest ranking.
The Persians remain at fourth place among the Asian teams. Australia is the best Asian team with 868 points, followed by South Korea (751) and Japan (740).
World and European champion Spain remained at the top of FIFA's monthly world rankings list, the Netherlands regained second spot and Argentina returned to the top 10.
The rankings weigh all international results over a rolling four-year period, and this month counted 91 matches including qualifiers for the World Cup and 2013 Cup of Nations, plus exhibition games.
Rankings (last month's positions in brackets)
1. (1) Spain
2. (3) Netherlands
3. (2) Germany
4. (4) Uruguay
5. (7) Brazil
6. (5) England
7. (6) Portugal
8. (11) Argentina
9. (8) Italy
10. (9) Croatia