While familial cases of Creutzfeldt-Jakob disease are extremely rare all over the world, 3 familial clusters were observed between 1983-2000 in a relatively small area situated in the North of Slovakia. Prevalence of CJD in this area exceeded the overall prevalence in Slovakia more than 8 times. The majority of CJD patients admitted consuming sheep brain. Most patients lived in small secluded villages with rather common familial intermarriage. CJD affected both sexes equally. All patients were prior to the disease mentally normal individuals. Shortly after the onset of CJD their mental status deteriorated remarkably with an average survival rate of 3.6 months.