Station officer Phil Roxburgh was one of more than 150 paramedics and other workers who gave written submissions to the Legislative Council committee, which is probing the service's management and operations.
Roxburgh on Friday told the committee he had seen morale fall, stress levels rise and cases of suicide increase in his 30 years with the ambulance service.
"And I hear stories from so many people who have come so close to attempting suicide, or who have gone through some really horrific experiences," said Roxburgh, who is based at Moruya on the NSW south coast.
Roxburgh is continuing to push for an investigation into the treatment endured by one colleague who committed suicide in 2005.
He said Christine Hodder had joined the ambulance service in 1999, and was the first female employee at a rural NSW station.
She was ostracised by some male colleagues, and Roxburgh said management then ignored complaints she was victimised.
Roxburgh said he was also targeted by colleagues for attempting to support Hodder, and his push for an investigation has led other workers to contact him with similar stories.
"What has scared me, with all the people that were phoning me and sending me emails, is we have a lot of people out there who are on the edge," he said.
"I refer these people to professional counselling but we need to the system to be looked at ... it needs to work better."
Other submissions to the inquiry complain of fatigue among paramedics workers who may be sent on late night on-call jobs while still having to front up for their rostered morning shift.
Paramedics also dealt with rising levels of violence in the community, according to submissions which also alleged key management personnel were focussed on undermining each other.
Liberal health spokesman Jillian Skinner said 593 ambulance officers had quit the service since 2002, and the "quitting rate is faster than the recruitment rate".
NSW Director-General of Health Professor Debra Picone conceded more work needed to be done to combat bullying within the service.
"The vast majority of people who work in the NSW ambulance service, from the top management to the paramedic, are decent and honourable people," Prof Picone said.
"However, I do believe that there are pockets of bullying and harassment in that organisation and I believe we have to work diligently to stamp that out."
