An elderly woman is fighting for life after being stabbed in the driveway of a home in Melbourne's north-east.

Police said the woman, aged in her seventies, was stabbed in the driveway of a home in Yerrawa Drive, Watsonia at round 12.30pm.

They arrested a 31-year-old Alphington man in the back yard of a property in Henry Street a short time later.

She was airlifted to hospital in a life threatening condition.