About a thousand workers have left Christchurch each month since the February earthquake, Inland Revenue figures show.
That has left some sectors short of skilled workers, with hotels, restaurants and retailers among the worst affected.
Canterbury Restaurant Association head Michael Turner told Nine to Noon that after the earthquake about 20 of his 30 employees left the city.
The shortage has been offset by about a third of the city's restaurants closing down.
Mr Turner says some hospitality businesses have been unable to get skilled staff and are unable to open.
"As the rebuild kicks in and restaurants come back on line we'll be looking for skilled staff, and it's a big concern that those skilled staff are just nowhere to be found."
Canterbury Development Corporation says it is working with Immigration New Zealand to help attract overseas workers as well as liaising with industry providers to train new staff.
However, it says the anticipated rebuild will bring many workers back to Christchurch and planning is underway to ensure there is enough accomodation available for them.