About 20 Hato Hone St John workers withdrew their work for four hours as a part of a national rally.
They made some noise and carried placards, including ones saying: "SOS — underfunded and undervalued" and "Striking for our rights, fighting for your lives."
First Union delegate Stefan Lozano said ambulance officers were underpaid and underappreciated.
They have been negotiating over pay and conditions with St John since the expiry of their collective agreement in December last year — but after nine months they felt there was no result.
"Obviously, the workers that are here had to withdraw from the work they love, but we feel we don’t have another option.
"We want pay equity, to be equal with professionals of the health sector."
He said it was hard to quantify, as there were different scales and positions, but he believed on average ambulance officers were paid about 20% less than other health workers.
Mr Lozano also said they were aware of the important job they carried out and the workers had a lot of pride in it.
But they felt they needed to be more valued by their employer.
"Emergency service is a very important job for the community. It is a life-saving service.
"Can you imagine what would be if someone has a heart attack and nobody shows up? It would be a disaster."
Mr Lozano said Hato Hone St John was operating at 70% of normal capacity during the strike and another work withdrawal was expected on Saturday.
