A first for the hospital, the scanner is the centrepiece of a $6.5million upgrade of the facility, which is expected to be completed in September.
The Siemens Go Top 128 slice scanner, which cost $1.07million, is only the second of its type to be installed in New Zealand, and the first in a public hospital.
Hospital operations manager Janeen Holmes said getting the scanner was an "important milestone" in improving health services for the residents of the Queenstown Lakes and Central Otago.
Until now, patients needing advanced imaging had to travel to either Dunstan, Dunedin or Southland Hospitals.
The lack of a CT scanner in the Wakatipu has long been a bone of contention between the community and the Southern DHB, particularly since a recommendation by a National Health Board panel in 2011 that one be based at Lakes District Hospital.
Clyde's Dunstan Hospital has had a scanner since 2013.
A medical radiation technologist at Lakes District Hospital, Elisabeth Key, said the radiology team was being trained to operate the scanner.
"We look forward to developing our skills in CT and providing a valuable service for the Wakatipu Basin and surrounding areas."
The scanner allowed faster diagnosis, which meant the best choices for patients could be made in a "timely manner", Ms Key said.
It was paid for with a grant by the Central Lakes Trust to the Lakes District Hospital Foundation.
Foundation chairwoman Jayne Macdonald said the new service would give the community a sense of "comfort and confidence".
"To have ready and immediate access to diagnostic equipment of this quality in the Queenstown Lakes district means that potentially life-saving decisions can be made here without delay.
"Our growing permanent and visitor numbers will mean the CT scanner is well-used."
CT scanners use X-rays to produce 3-D pictures of the inside of a patient's body.
