For the past few months delicate excavation work has been undertaken to ultimately give as many of the soldiers as possible a named gravestone in a new cemetery built near by.
The decision to start full-scale DNA testing has been made after an initial study which examined a cross section of the Fromelles remains.
Samples were taken from the teeth and bones of remains found in different parts of the burial sites to assess the overall quality and quantity of DNA that could be expected to be obtained.
It is thought that around 250 to 300 soldiers are buried in the grave pits, while a number of artefacts have also been excavated including remains of a gas mask and even a paper train ticket for a second class return from Fremantle to Perth.
The project is being backed by the UK and Australian governments, with UK veterans minister, Kevan Jones, saying: "This is an important step forward in the process of trying to identify the World War One soldiers buried at Fromelles.
"DNA is just one part of the identity puzzle and our experts will be examining all available evidence in their attempts to confirm the identities of these men. Each one of these soldiers will be laid to rest with the dignity they deserve and we owe it to them to do all we can to identify them."
Families who believe their relatives may have lost their lives at Fromelles are urged to check the lists of casualties at www.fromelles.org.
Some of the items recovered from the burial pits: