More than 140 family members have registered their interest on Facebook to attend what will be a "humongous family reunion" in Wairarapa and more are expected.
The Wyeths, one of Masterton's oldest families, will be celebrating a 175-year reunion since their ancestors arrived in New Zealand in 1840.
Lyn Tankersley, a member of the Wyeth family, is excited for what will be the second Wyeth family reunion she has attended.
"There are around 140 people on the Facebook page wanting to attend but I expect there will be more who say they will come closer to the event," she said.
"I would say probably 200 to 300 people will attend which really is a humongous reunion."
Family members will be coming from all over the world, from as close as within Wairarapa to as far away as England and Australia.
"It's a pretty amazing feat," Mrs Tankersley said.
"The Wyeth family would be one of the biggest New Zealand families."
The New Zealand Wyeth family ancestor Robert Wyeth arrived in Petone from London aboard the ship Cuba in January 1840.
Jane Wyeth, formally Jane Runnalls (Reynolds) arrived a month later.
They married that April and had 12 children, 9 of whom survived to adulthood.
Mrs Tankersley, who attended the 150-year reunion in Upper Hutt, said that even though the event was a long time ago she was fond of the memories she made with family.
"Looking back, I have an amazing memory of that time," she said.
"We will be posting a video of the 1990 reunion on the 175th Wyeth Reunion Facebook group."
Family members who attended the 1990 reunion pledged to meet again and "it is now time to come together 25 years later to celebrate our pioneering ancestors."
The New Zealand Wyeth family will be reuniting in Masterton from October 9-11 based at Rathkeale College.
Registration to attend the event has been extended to the end of August.
Reunion weekend activities will include a bus tour, group photos, and family meals.