The effectiveness of homeopathic treatment in the case of subclinical bovine mastitis was assessed. 39 cows with 65 udder quarters, infected with environmental associated pathogens, were treated. Two therapeutical methods, classical homeopathy and antibiotics were compared to the application of a placebo. Milk samples were collected for bacteriology and milk somatic cell count. The results showed that the cure rate was on a low level. The success of homeopathic therapy (7 %) was in midway between antibiotics and placebo. It can be concluded that the homeopathic treatment is not recommended for the therapy of subclinical bovine mastitis caused by environmental associated pathogens