BreastScreen NSW clinics will gradually re-open to provide free mammograms again after closing when staff were redeployed to help with the pandemic.

BreastScreen NSW will resume providing free mammograms for women after the service was suspended because of the COVID-19 pandemic.

All screening services across NSW were suspended in August after some clinics had already closed across Greater Sydney and some regional areas in June.

BreastScreen NSW director Sarah McGill said it had been a "very difficult decision".

"This decision was made in response to the increasing risk posed by the COVID-19 Delta strain and the need to redeploy staff to support the pandemic response at every local health district across the state," she said at the government's daily COVID briefing on Tuesday.

"I'm pleased to advise today that we are now working towards resuming services across the state on a case-by-case, site-by-site location."

The service has already resumed on the mid-north coast, north coast and Hunter New England local health districts, Coffs Harbour, Lismore, Port Macquarie, Tamworth, Narrabri and Scone.

There were also mobile services operating in in Kyogle, Casino and Grafton.

"Women who have had their appointment cancelled due to the temporary suspension will be contacted by their local services and allocated a prioritised booking," Ms McGill said.

A range of COVID-19 safe measures have been implemented at clinics and mobile screening services to protect women, staff and the wider community.

Any women with symptoms like a lump, changes to the breast, dimpling of the skin or any other changes in breast tissue should get checked as a matter of urgency as services resume at clinics in the coming weeks and months, she said.