Klebsiella mastitis usually occurs sporadically, but in Finland and elsewhere Klebsiella epidemics have recently been described in large dairy farms. Prognosis for Klebsiella mastitis is poor and the infected cow is usually prematurely culled. In the case described, of about 100 cows 15 developed coliform mastitis, of which nine were caused by Klebsiella. Klebsiella was also isolated from the automatic milking unit and the immediate environment. The situation was controlled by improved milking hygiene and culling. On farms with an automatic milking system, in addition to the routine washings made by the system itself, the milking robot and parlour should be cleaned daily.