Thousands of campaigners formed a human chain around the Vale of Leven Hospital in protest at planned cutbacks.
Thousands of protesters encircled the Vale of Leven Hospital
Up to 4,000 encircled the building in a bid to stop Argyll and Clyde health board's plans to move many services to Paisley's Royal Alexandra Hospital.
In June, local health chiefs unveiled cuts to its service aimed at curbing a £42m budget overspend.
Local MSP Jackie Baillie said the scale of the protest was testimony to the depth of feeling in the community.
Ms Baillie, who addressed protesters before the event in Alexandria, said: "There were 4,000 people there at least: children, babies in harnesses, grandparents.
"People from across the community came out to support
"We could probably have held hands around the hospital three times over because there were so many people there. It was really, really positive."
She labelled the planned downgrading of services as "indefensible".
The protestors were supported by several unions, despite the fact that pay rises to many of their members form part of the financial problems faced by the health board.
GMB Scotland spokesman Jim Moohen said: "We don't put a cost on human life or any tragedy that can occur.
"We believe that the transfer of facilities here to Paisley will result in tragedy."
The Dunbartonshire hospital was forced to close its A&E department following the resignation of a surgeon and currently has a minor injuries unit.
But under the health board's radical plans any patient needing emergency care would have to travel to Paisley for treatment, which is at least 15 miles away.
The board claims new rules over doctors working hours have made smaller hospitals, like the Vale of Leven, more difficult to staff and more expensive to run.
In a consultation paper, it warned some services would collapse if changes were not made.
The plans for hospital services in the area, which would also affect Inverclyde Royal Hospital, are up for public consultation until October.
A reported 22,000 people have already signed a petition against the plans.