An elderly woman was found lying in a pool of blood after a horrific attack on the footpath of a suburban street in Melbourne's west.

It is believed the 77-year-old woman was out walking her dogs just before 8pm on Thursday, when she was bashed and left with life-threatening head injuries on the driveway of a Willaton Street house in St Albans.

The Willaton Street home in St Albans where an elderly woman was found with life-threatening injuries. Credit:Anna Prytz

A passerby saw the victim lying on the driveway and raised the alarm.

The woman was taken to hospital in a critical condition.