The FSA has revealed almost one member of staff left per day on average over the last year, doubling the previous year's rate.
Ahead of the split-up of the regulator, which will be completed in early 2013, 352 employees quit the FSA over the past 12 months compared with 181 the year before.
The revelations came in response to a Freedom of Information request from the Independent with the FSA attributing the increase to changing economic conditions.
Kathleen Reeves, human resources director at the FSA, said: "Staff turnover levels fell during the crisis but are now starting to return to the level you would expect as recruitment picks up in the financial services sector."
The FSA added last year's departure rate was on a par with 2006-07, when 326 staff members left, and 2007-08, when there were 355 departures, although just 206 staff employees quit in 2008-09.
Last month, it was revealed the FSA's frontline staff enjoyed an average salary rise of 22% to £51,232 between 2005-06 and 2009-10.
Meanwhile, senior management salaries rose 14% from £206,391 in 2005-06 to £236,950 in 2009-10.
More than £167,000 raised
Beware ‘temporary’ vulnerability
Celtic WM and Active Wealth