Campylobacter jejuni contamination was surveyed in samples collected from the breeder-multiplier houses, broiler houses, feed mills, hatcheries, and processing plants of two integrated broiler firms. Insects and mice were also trapped at each location. C. jejuni was most frequently found in samples collected from processing plants, followed by samples collected from broiler houses, and breeder-multiplier houses. Samples obtained from feed mills and hatcheries were negative, suggesting that the C. jejuni was not transmitted by either feed or eggs. C. jejuni was also not isolated from insect or mouse samples. However, the external surfaces of insects were sanitized with a chlorine solution, prior to analysis. Thus, these data suggest any contamination of insects with C. jejuni is generally external not internal. Contamination in broilers apparently originated from some unknown source(s) in broiler houses. C. jejuni was isolated from 20% of the cloacal swabs taken as birds entered the plant, 52% of the carcasses sampled following immersion chilling, and 31.6% of whole broiler carcasses sampled at retail outlets. While these data suggest that cross-contamination occurred within processing plants, field control methods would appear to be necessary for control of C. jejuni in modern broiler production and processing systems. The frequent C. jejuni isolations from dead birds in broiler houses suggested the regular collection of normal mortality as one farm management procedure that might help reduce Campylobacter contamination in broilers.