Valais is Switzerland's largest wine-producing region, stretching along the Rhône Valley in the country's southwestern canton. The vineyards extend from the glaciers of the Rhône Glacier near Gletsch down to Lake Geneva, with most plantings concentrated between Martigny and Leuk. This alpine valley produces approximately one-third of Switzerland's total wine output, making it the most significant wine region in a country where viticulture dates back to Roman times.

The region benefits from a continental climate with strong Mediterranean influences, protected by the surrounding Alps which create a natural rain shadow effect. Valais receives exceptional sunshine hours, often exceeding 2,000 per year, while annual precipitation remains relatively low. The vineyards are planted on steep terraced slopes and alluvial fans, with elevations ranging from 460 to 1,100 meters above sea level. Soils vary considerably, from limestone and schist in the upper valley to glacial deposits and alluvium in the lower sections.

Valais cultivates both international varieties and indigenous Swiss grapes, with Chasselas and Pinot Noir representing the largest plantings. The region is particularly noted for its native white varieties including Petite Arvine, Amigne, and Humagne Blanc, as well as specialty reds like Cornalin and Humagne Rouge. These indigenous varieties have adapted to the high-altitude conditions over centuries and produce wines with distinctive mineral characteristics. The combination of intense sunlight, cool nights, and diverse microclimates allows for remarkable diversity in wine styles, from crisp whites to concentrated reds and occasional sweet wines from dried grapes.