The authors describe the epidemic incidence of diseases caused by Campylobacter jejuni/coli. During the 5-week follow up period (June 1-July 1, 1988) a total of 74 subjects fell sick. In 31 instances the suspect factor of transmission was non-pasteurized cheese prepared from sheep's milk. In this group of patients a significant shift to higher age categories was noted, contrary to the other 43 diseases. It did not prove possible to isolate Campylobacter from cheese, smears from the cottage or from rectal swabs of the workers from the cottage. In an investigation focused on assessment of survival of Campylobacter jejuni/coli in sheep's milk and cheese long-term survival of the microorganism only in non-pasteurized milk was found. The authors assume that cheese becomes contaminated secondarily, by lack of adherence to hygienic rules.