The team, consisting of Amber Barker, Natasha Hancox, Tanya Toogood and her sister Amanda Green from Melbourne, joined 550 teams on the endurance fundraising walk through rugged bushland joining Brooklyn to Mosman this weekend.

Mrs Green was an Oxfam Trailwalk veteran, however, Mrs Toogood said "the rest of us are new to long walks in the bush".

The team tackled wet and muddy conditions, completing the challenge in 38 hours and 37 minutes.

"We are all pretty excited we've done it together and we are happy we've finished it," Mrs Toogood said.

"The mud was awful.

"There was a few times each one of us felt a bit overwhelmed but we just kept going so that was good."

She praised the team's support group.

To prepare themselves, the mums have been in training since January, regularly hiking up and down North Brother Mountain.

"We go out in all conditions, including in the rain, the dark and the heat," Mrs Toogood said.

The sleepless nights associated with raising eight children, including Mrs Barker's three-year-old triplets, was probably the best preparation for the event's requirement to walk through the night.

The Oxfam Trailwalk website promises: "it's tough, but the feeling when you cross the finish line will be something you'll never forget".

According to the race rules, the event is not a relay.

Teams must start together, stick together and finish together, within 48 hours. They must also commit to raising at least $1,400.

The ambitious quad have already surpassed their original target, raising more than $3000.

Mrs Toogood explained that the purpose of the annual walk is to raise funds for Oxfam, so they can asssist communities around the world to help them create their own sustainable solutions to poverty.

To donate online or follow the team's fundraising progress go to www.trailwalker.oxfam.org.au/team/home/17656