India and Turkey host the most fake Facebook accounts, according to the social network.
There are 143.3 million false and duplicate Facebook accounts, and most come from developing countries including India and Turkey, it said.
In its US Securities and Exchange Commission (SEC) filing, Facebook noted that about 7.9% of its accounts are duplicate, while up to 2.1% and 1.2% of them are user-misclassified and "undesirable", respectively.
Facebook said in its filings that the percentage of accounts that are duplicate or false is markedly lower in developed markets such as the US or the UK and higher in developing markets.
"We estimate, for example, that duplicate accounts may have represented between approximately 4.3 - 7.9% of our worldwide MAUs (monthly active users) during the nine months ended September 30, 2013," the social networking site added.
Citing Facebook filings, PTI revealed that the social networking firm's MAUs reached 1.19 billion by the end of September.
"We also seek to identify false accounts, which we divide into two categories -- user-misclassified accounts and undesirable accounts," the filing read.
"During the nine months ended September 30, 2013, for example, we estimate user-misclassified accounts may have represented between approximately 0.8 - 2.1% of our worldwide MAUs and undesirable accounts may have represented between approximately 0.4 - 1.2% of our worldwide MAUs."
Recently, Facebook admitted a decline in its usage amongst young teenagers mainly down to mobile-first social apps including Snapchat.
During Q3, the firm reported a 60% rise is its revenues to $2bn for the quarter, up from $1.26bn for the corresponding period last year.