A total of 161 strains of Campylobacter fetus subsp. jejuni were isolated from house flies (Musca domestica). The carrier rates detected were 50.7% in flies captured on a chicken farm and 43.2% in flies from a piggery. The relative prevalences of Campylobacter coli, C. jejuni, and nalidixic acid-resistant thermophilic campylobacters were 90.1, 6.2, and 3.7%, respectively. The results indicate that flies may play a linking role in the epidemiology of Campylobacter infection in humans by transmitting campylobacters from animals to human food.