Laura Shepherd is taking an early retirement from the centre based in the Brown Building, Gorebridge.
Mrs Shepherd, 55, has played a key role in developing volunteering in Midlothian, steering the Volunteer Centre through many changes over the years.
She also assisted in setting up many local clubs, including St David's Bradbury Day Centre in Newtongrange, which celebrated its 20th anniversary last year.
After attending Edinburgh University, Mrs Shepherd volunteered at a youth group and taught English at schools in Sudan and Algeria.
On moving back to Edinburgh, she worked for a small volunteering group for 18 months before it closed. Then she noticed an advert for a short role at a volunteer centre in Midlothian.
"I had some suitable experience so I got the job," Mrs Shepherd said. "At first it was just for a year, but 25 years later I was still there."
In those 25 years, Mrs Shepherd has seen the district change from a mining area to a place for commuters to live.
"Different sorts of people started coming in, so there were a lot of changes," she said. "But it's still a community-minded place and the people of Midlothian are very friendly. It made the job a lot easier."
In her time at the centre, Mrs Shepherd most enjoyed matching people who wanted to volunteer with those who needed volunteers. "I enjoyed seeing people getting a lot out of it," she said.
She also saw many people who had overcome their own difficulties returning to share the benefit of their experience.
"It's satisfying when people have problems and volunteer for projects," she said. "You see their self esteem and confidence grow. It's quite amazing to see the difference it can make to them."
She added: "Getting sufficient funds was the biggest problem. People had to work shorter hours and we moved premises. That was a stressful time."
When funding from the council fell last year, she decided she should move aside for a fresher face. Taking over is Anne Moodie, who has considerable experience of working with volunteers. Ms Moodie said she hopes to "build on the volunteer centre's existing strengths to ensure that it is an accessible and welcoming organisation which inspires people to volunteer".
The centre bid farewell to Mrs Shepherd with a commemorative silver quaich.
She plans to relax and spend more time with her husband Bill.