Two tradesmen rescued an elderly woman from her burning home in Melbourne's south-east on Wednesday morning.

The concrete workers came to the 89-year-old's aid when they heard a loud noise and saw smoke coming from the tiled roof at the back of the house in Atkinson Street in Bentleigh just before 8.30am.

MFB acting commander Paul Juhlin said the tradies were working on a path at the property when the blaze began.

He said if it hadn't been for their bravery and care, the woman may have not survived the fire.

""They looked through the front window and saw flames at the rear of the house and tried to alert the woman," he said.