The Southland branch is celebrating its centenary on October 19 with a high tea in Invercargill.
Jeanette McIntyre MBE, of Gore, was the president of RWNZ from 1991-1995.
She said the voluntary body had made significant charitable contributions since forming in 1925 as well as important "little things" along the way.
Across 100 years, they had raised money for medical research, funded war efforts and set up institutions to help rural women and their families.
"Those are just some of the things that we do, but a lot of it's done quietly in the background," she said.
RWNZ was formed when a group of farmers’ wives accompanied their husbands to a 1925 Farmers’ Union, now Federated Farmers, conference in Wellington.
Mrs McIntyre said conversations about rural challenges and limited access to services between the wives highlighted a need and the organisation was formed.
Due to the meeting’s circumstances, it was originally called the Women's Division of the Farmers' Union.
RWNZ had raised over $70,000 for cot death research and "a lot" for leptospirosis, a bacterial infection contracted from animals and common in farmers.
The Bush Nursing Scheme they started in 1927, was the "forerunner" for district nurses, Mrs McIntyre said.
Their rural housekeeping scheme was sold as a business, becoming Home Care and later Access Community Health.
They also invested in forestry near Winton in 1948, that continued to fund their charitable donations.
Of historical significance was the women’s support of the war effort, where they raised £5000 in one month and bought a Spitfire plane.
When she became national president in 1991, Mrs McIntyre began planting seeds to move away from the Federated Farmers’ name.
She said people would come up to her at functions and ask if they were part of the Federated Farmers, she would have to explain they were their own organisation.
She had some initial push back with the name change but the organised ultimately transitioned in 1999.
"In our own right, as we always had been," she said.
The "little things", such as supporting Hospice NZ, Southern Cancer Society and the arts, were important to her.
Their membership of about 2000 was smaller than it once was, as "life was very different now".
Mrs McIntyre was keen to celebrate the past and also the future.
To mark the centennial, the Southland RWNZ had chosen Anderson Park in Invercargill, as the Anderson and McKenzie families were "tied up" in the original 1925 meeting.
Mrs McIntyre said the high tea would be accompanied by some beautiful old cars and a possible appearance by farmer’s wife cartoon character Edna, with the spotted dress.
