From April 1998 to March 2000, 18 broiler flocks were followed from the hatchery to the slaughterhouse. Campylobacter was not found in the hatchery, 1-day-old chicks or in the rearing house before the arrival of the chicks. The infection of broiler flocks increased continuously during the rearing time, with a total of seven positive flocks at the end of rearing. Farms with Campylobacter-positive broilers were characterized by the circulation of Campylobacter in the environment (puddles, dung hill) and on the footwear of the farmer. The administration of antibiotics did not significantly reduce Campylobacter shedding. With the exception of one flock during rearing and a few flocks in the slaughterhouse with a mixed Campylobacter coli-Campylobacter jejuni infection, C. jejuni exclusively was found both during rearing and on the carcasses. A significant correlation exits between the contamination of the broilers during rearing and the carcasses after processing. No slaughterhouse was able to avoid contamination of carcasses when status-positive animals were delivered. Moreover, six negatively delivered flocks yielded positive carcasses, the result of a supplementary contamination, which occurred during transport and slaughtering.