Campylobacter and Salmonella are normal gut flora in many healthy meat chickens. In an AgriFutures funded project, we have generated the following data:- A) a national snapshot of the prevalence and levels of Campylobacter and Salmonella in representative processing plants Australia-wide; and B) the natural variation that occurs in the presence and level of the same pathogens over time (at the seasonal level and at the day level). Samples were collected from six processing plants Australia-wide twice in the year for each plant, in winter (May-August) and summer (October-February). Repeat sampling was done on three consecutive days in a week for three consecutive weeks in both seasons. Each day, 10 chickens were sampled at two points, individual caeca (at evisceration) and carcass rinses (after chill/before packaging). The presence and levels of Campylobacter and Salmonella were determined using Australian Standard Methods. A total of 93.5% of caeca and 69% of carcass rinse samples were Campylobacter-positive. The mean Campylobacter count in the caeca was 6.87 log10 cfu/g (winter) and 7.28 log10 cfu/g (summer); and in carcass rinses was 3.97 log10 cfu/carcass (winter) and 3.93 log10 cfu/carcass (summer). For Salmonella, 2.7% of caeca and 5.4% of carcass rinse samples were positive with variable levels of Salmonella. In the caeca, the levels were between <3 to 1100 MPN/g whilst in the carcass rinse samples the levels were between <0.3 to 110 MPN/ml, with 56.5% of samples recording <0.3 MPN/ml. While summer caecal Campylobacter counts were significantly higher than winter counts, this seasonal variation did not occur in the carcass rinse samples at the end of processing. One processing plant had significantly higher levels of Campylobacter-positive samples than the others. No seasonal variation occurred for Salmonella (either the caeca or the carcass rinse samples) although once again one processing plant had significantly higher carcass rinses numbers. As only one winter and one summer was studied, our observations may simply be what occurred in 2019/2020 seasons.