Murray Darling is the second largest region of the Big Rivers viticultural zone – and indeed the whole of Australia. It is responsible for up to one-quarter of all wine produced on the continent every year, depending on seasonal variations. This is mostly wine destined for sale in bulk rather than under premium labels. It is produced from 25,000 hectares of vines owned by more than 1,000 growers. The region extends from the border of Victoria with South Australia in the west, to Balranald in New South Wales in the east. Although it is divided neatly down the middle by the Murray river, the region's vineyards are mainly located on the southern, Victorian side.

The Murray Darling climate is of continental type – hot and dry with very low rainfall. Such is the sunny nature of this climate that the area has become known unofficially as Sunraysia. The lack of humidity here helps to keep the vines free from fungal diseases such as mildew, and assists in guaranteeing the high yields so important to the region's place in the Australian wine industry.