In Austria, grassland accounts for more than 50 percent of agricultural land and is mainly located in mountainous regions. Consequently, 70 percent of all Austrian dairy farms, producing two thirds of all milk, are located in these areas. In the Alpine regions, organic farming has traditionally been very important and represents a significant share (more than 18 percent in Austria) of all farms and land areas. In mountainous regions, production can be restricted by climatic and geomorphological factors. Therefore, high input farming systems are rare in the disadvantaged regions and many farms take part in the Austrian programme to promote agricultural production methods compatible with the requirements of the protection of the environment, extensive production, and the maintenance of the countryside (ÖPUL). In comparison to conventional farms, milk yield per cow per year and proportion of concentrate and corn silage in the total ration are both lower, while the proportion of green fodder and grazing is higher. The Cooperative Organic Dairy Hatzenstädt, which currently comprises 39 small dairy cattle farms, is located in Kufstein, Tyrol, an Alpine province in Western Austria. Established in 1937, this cooperative dairy plant started taking milk exclusively from organic farms in 1990. 1.7 million kg of milk are delivered to the cooperative annually, processed mostly into hard cheese (e.g. organic Emmental and Alpine cheeses) as well as other organic dairy products. The number of livestock units per hectare across all member farms, of which about 20 percent are run by full-time farmers, varies from 8 to 35. About 10 percent of the dairy products are sold directly in a local store owned by the Dairy Hatzenstädt, while the other 90 percent of all products are delivered to supermarkets and stores for natural or health-related foods or distributed via Marketing Cooperative Bio Alpin. The current average producers’ milk price is € 0.55 per kg. This study describes the results of EU research project SOLID (Sustainable Low Input Organic Dairying). 12 members of the Dairy Hatzenstädt were selected for a rapid sustainability assessment, and a biodiversity survey of grassland vegetation and non-crop habitats was conducted on 10 of the 12 farms. This study demonstrates that organic milk production can be viable with minimum supplementation strategies. Appropriate feeding strategies can contribute to improving the sustainability of Alpine farming systems.