Contamination of broiler carcasses during processing with several microorganisms as salmonella, campylobacter, E. coli and staphylococcus aureus is frequently occurring. Scalding, defeathering, chilling are critical points at which cross contamination may occur during processing. Recently several interventions for carcass decontamination have been employed in order to reduce the levels of microbial hazards on poultry carcasses during processing; among which chlorine and organic acids are the most common. This study was carried out in a traditional poultry abattoir in Fayoum Governorate in order to improve the microbial quality of broiler carcasses. During 10 replicate a total of 160 carcasses were collected at 4 sampling points in the processing line (scalding, defeathering, final wash and chilling). Bacterial counts recovered from broiler carcasses rinse were lowered by 1.3, 1.3, 0.3 and 0.5 Log₁₀ cfu\ ml after treatment of scalding water with 100 ppm Calcium hypochlorite in scalding. Adding peracetic acid (PAA) 50 ppm + 0.5 % acetic acid to the defeathering machine spraying system during defeathering lowered the count of coliforms and faecal coliforms significantly (P ≤ 0.05) by 1.5 and 1.6 Log₁₀ cfu\ ml of carcass rinse, while it wasn't significant for E. coli and staphylococcus counts (1.2 and 0.95 Log₁₀ cfu\ ml), respectively. Furthermore, significant differences in the reduction of all bacterial counts were observed in the washing stage (P ≤ 0.05) after treatment of broiler carcasses with a mixture of lactic acid 1 % + acetic acid 1 % in the final washing step. At chilling stage Na hypochlorite 50 ppm reduced the bacterial counts by 2, 2.2, 1.3 and 0.8 log₁₀ cfu\ ml of carcass rinse for coliforms, faecal coliforms, Escherichia coli and staphylococcus aureus, respectively. E. coli, salmonellae, staphylococcus aureus and campylobacter spp. were reduced by different percentages. The used interventions effectively or significantly reduced microbial populations on broiler chicken carcasses during processing.