Parents and children from St Joseph's Primary in Milngavie were part of the group who were objecting to proposals to combine the school with St Andrew's in Bearsden.
More than 200 people gathered outside East Dunbartonshire Council Buildings in Kirkintilloch, banging drums and holding banners in a colourful demonstration.
The proposals will see St Joseph's pupils transfer to Bearsden in 2016, in a move that will cost nearly £9 million.
The vote ended at 14 to 10 for the proposals with councillors Maureen Henry and Eric Gotts, who represent Milngavie, both voting in favour of the changes.
Laureen McIntyre is chairwoman of the parent council, and has fought to stop the merger.
Both her sons, James and John, attend St Joseph's.
She said: "There are several of us within the parent council who are angered by the attitude of councillors.
"We feel like they have been dismissive, disrespectful and patronising.
"Councillors keep going back to the educational value it will have, but nobody says what the edu-cational value is, and there is no proof there even will be one."
"It is not over, we are all going to keep fighting.
"We plan to take it to the Scottish Govern-ment now, and will take legal action of we have to."
Emma Whitfield, a member of the parent council, was also at the council building to take part in the protest.
Her three children all attend the school, and she is outraged at the decision, claiming that councillors have not listened to the demands of the electorate.
She said: "Our parent council doesn't want it and neither does St Andrew's. We have both said this is wrong, but are not being listened to by our councillors.
"The council's argument may be that there are educational benefits from a new school, but I think there are much more important things than a shiny new building."
Councillor Rhondda Geekie, leader of East Dunbartonshire Council, said it consulted all the necessary groups.
She said: "This is a complex issue and we have taken all the evidence and feedback from our consultation on board in making these decisions.
"We will continue to work with all of our stakeholders in delivering the new schools, which we believe provide the best educational outcome for these young pupils."