The survival of Mycoplasma bovis was examined on or in different sterilized carriers which normally may have contact to cows (sponge, cotton, wire, glass, wood, straw, tap water, milk). At 4 degrees C M. bovis survived on sponges 57 days, in milk 54 and in Mycoplasma medium for 50 days. At 20 degrees C survival time was 1 to 2 weeks, at 37 degrees C 1 week.