The Royal Australasian College of Surgeons says it would be better for patients if the South Island's six neurosurgeons were all based in one centre.
A panel set up by the Government has recommended the specialists be centralised in Christchurch.
However, an estimated 10,000 people marched in Dunedin on Friday demanding that the city keep its neurosurgery unit.
The College of Surgeons says basing the neurosurgeons in one place would mean they could call on each other for backup and co-ordinate closely with other medical services.
