At least 4,000 people took part in a march in Whitehaven as part of a campaign to try to preserve hospital services in the west of Cumbria.
The trust responsible for the West Cumberland Hospital said a new hospital would be built, but it did not yet know what services it would provide.
Local people are worried that services at the hospital will be downgraded.
Health bosses said they were looking at the best way of delivering health care across the county.
The Royal College of Nursing is supporting the march on Saturday, which was being attended by local health care workers and councillors.
Cumbria Primary Care Trust and North Cumbria Acute Hospitals NHS Trust bosses said that the public would be fully consulted over plans for a new hospital.