Dwindling numbers of new nuns entering the order has been blamed for the pending closure of the Ashmont monastery, with just three Sisters remaining.

Wagga Monastery Superior of the House Sister Maria told The Daily Advertiser that changes to the culture of society had led to less of a demand for religious vocations.

"Our tradition has been around for 800 years and that history has gone through the full cycle of flourishing, diminishing and re-flourishing according to the times," she said.

"It's very sad indeed for us now to be at this phase ... to see the numbers diminishing when the need is so great.

"It's very big, it's on a huge acreage here ... it can't be maintained with so few numbers."

The Carmelite nuns are probably best known in Wagga for selling lamingtons as a fundraiser.

Sister Maria said it was "a major source of income" that helped improve the monastery building but demand became so great it was deemed it to be an interference with the order's divine purpose.

"I don't think we have ever been forgiven for stopping it," Sister Maria said.

"I still meet people in the street and they ask 'are you going to produce those lamingtons again?'."

The monastery will hold a Closure Mass on November 6 with numerous guests, including the Archbishop of Canberra and Goulburn Christopher Prowse.

The monastery and memorial shrine, also known as 'The Carmel of Our Lady Queen of Peace', was founded in 1966.

"(In 1966) we were busting at the seams; the monastery in Melbourne had so many applicants," Sister Maria said.

Construction started on the monastery at Ashmont in 1967, with the first Mass held in 1968.

The three sisters will return to the Carmelite order's head monastery in Melbourne, but Sister Maria does not know what will happen to the Wagga building.

"The fact that we are leaving is a tremendous sadness for us all, it is a real period of grief for all of our friends," she said.

"But they realise you can only live in the circumstances that you do live, which are not always the ones you would ideally like but this is how life pans out."