The Super Eagles have slid down by seven places in the latest FIFA rankings which were announced on Thursday.
The 2013 African champions fell from 59th to 66th, dropping 41 points from 582 to 541.
Nigeria had also dropped seven places from 52nd to 59th last month, making it a cumulative drop of 14 places in just two months.
The Super Eagles played two matches in November, a goalless away draw with Swaziland and a 2-0 home win against the same opponents.
Nigeria's ranking in Africa is now 14th, behind the likes of Uganda and Mali.