Parliamentary Service had a staff turnover of 16 percent this year - the highest its ever had.
That's right across Parliament and corporate support.
Parliamentary Service general manager David Stevenson said a combination of an aging workforce and graduates who come and work at Parliament for a short time as reasons why turnover might be so high.
He said it always has a higher turnover after an election and that would have played a part too.
"There's always an interesting dynamic with elections, people stay for an election and then move on," he said.
"I can't say that's the whole driving force behind that 16 percent number... but it is very much this time that we see quite a lot of people deciding to move on after an election."
But ultimately Mr Stevenson said it doesn't come down to one or two things.
"There's various factors as to why people leave the service. There are relationship issues, there are various career progression opportunities for staff," he said.
Mr Stevenson said he hasn't been alerted to any certain behaviour that's driven people away, but he's still worried about the numbers leaving.
"It's a little bit of a concern, it's never been that high. We monitor it quarterly and 16 would be the highest it's been for a while."
He said the average turnover rate is around 10 percent and the amount of time that someone works for Parliamentary service is five and a half to six years.