Facebook's Irish operation paid only €3.23m (£2.6m) in corporation tax last year, even as revenues at the company surged past the €1bn (£0.8bn) mark.
Accounts just filed for Facebook Ireland Ltd show turnover more than quadrupled from €229m (£186.5m) to €1bn (£0.8bn) during 2011.
Despite that, the firm slumped to a loss of €18m (£15m) - a year after recording a €1.8m profit.
Facebook, like a number of US firms operating in the Republic, uses a perfectly legal tax avoidance technique, known as the Double Irish, which sees the company pay royalties to another company, usually based offshore.
In this case, Facebook Ireland Ltd paid Facebook Ireland Holdings for licence expenses relating to the use of the Facebook Platform. Those royalties topped €1bn (£0.8bn) in 2011, compared to €221.6m (£180m) in 2010.
Staff and executive directors received shares worth €13.95m (£11.4m) during the year, however, €5.9m (£4.8m) of these went to unidentified key management personnel.
Mark Zuckerberg's social network floated in May at a valuation of close to $100bn (£61.4bn). The company is now worth about $60bn (£37bn).
The quadrupling of revenue came from the company "billing third-party customers for online advertising on the Facebook website" for the 12 months of 2011 compared to four months in 2010.
The Irish business now accounts for some 40% of the network's global revenue.