Arcobacter species were isolated from faeces of healthy cattle on three unrelated Belgian farms, using a quantitative isolation protocol. Isolates were identified by m-PCR and characterized by modified ERIC-PCR. The Arcobacter prevalence on the three farms ranged from 7.5 to 15%. The prevalence in dairy cattle ranged from 5.9 to 11% and for young cattle and calves, the prevalence was determined as 18.9 and 27.3%, respectively. Of the 276 animals examined, eight had a bacterial load of more than 10(2) cfu/g faeces and low levels were detected in 22 animals using enrichment. The Arcobacter excretion ranged from 0 to 10(4) cfu/g faeces. Arcobacter cryaerophilus was the dominant species isolated from cows, but co-colonizations occurred in 26% of the Arcobacter excreting animals. Characterization of the 164 isolates showed a large heterogeneity and animals could be colonized with more than one genotype.