This study is the first to quantify the Campylobacter contamination in chicken farm waters. Water samples from 10 broiler chicken farms in Khon Kaen, Thailand, were collected during winter, summer, and rainy season. Four types of water i.e. 3 drinking water, 1 main tank water, 1 evaporative pond water, and 1 environmental water sample were collected at each farm twice during 1-15, and 16-35 days of rearing. In total, 360 water samples were sampled. The overall occurrence rate of contamination was 0.3% (1/360). Only 1 environmental water sample (1.7%, 1/60) was found contaminated with Campylobacter species. Water collected during the later stage of rearing (16-35 days) was positive for Campylobacter spp. contamination. The extent of contamination was greater than 230 MPN/100 ml. However, drinking and main tank water were free of Campylobacter spp. contamination.
