Veterinary medicine, dairying, and consumers are likewise interested in mastitis control. The veterinary point of view includes health and function of the udder as well as the production of milk of hygienic quality. Investigations in 6 dairy farms showed that a mastitis control program improved the udder health and resulted in economic benefits. Up to 67% of the subclinical infected udder quarters could be eliminated by prophylactical control measures, especially teat dipping and dry cow therapy. The frequency of clinical udder infections was reduced by about 50%. Furthermore in the first year 5.1% and 7.1% increase of milk and fat yield respectively could be noticed for cows being subject to the program for the whole time. These values could not be reached in the second year. In one herd the milk production increased by about 10% after a control period of two years. The owner of this herd (ca. 35 cows), who was very engaged in the program, obtained an economical benefit of ca. 3500 DM in the first and 7300 DM in the second year of the program. This realised a profit of1.85 DM in the first year and 3.85 DM in the second year per each DM cost in the control program. Mastitis as well as control measures do not implicate a special risk for the human health, because food and drug regulations enable the protection of the consumer in an optimal manner.