This study aimed to assess biofilm formation capacity of Salmonella, E. coli and Staph. aureus isolated from poultry abattoirs as well as evaluation of efficacy of disinfectants against biofilms produced by these bacterial species. Therefore, 100 samples were collected from two poultry slaughterhouses at El- Sharkia governorate, Egypt. After that biofilm formation capacity of the tested bacterial species was assessed by microtiter plate (MTP) method. Additionally, the efficacy of five disinfectants commonly used in poultry abattoirs including hydrogen peroxide, sodium hypochlorite, virkon S, glutaraldehyde, and copper sulphate with different concentrations (1, 2 and 5%) and different contact times (10, 60 and 120 m) on removal the biofilms produced by S. Typhimurium, E. coli O2H6, and Staph. aureus was evaluated. Out of 100 collected samples, 10 (10%) strains were identified as Salmonella, 40 (40%) strains were E. coli as well as 35 (35%) were Staph. aureus. 90%, 92.5% and 91.4% of the isolates of Salmonella, E. coli and Staph. aureus were biofilm producers. Virkon s was the most powerful disinfectant which removed 98.6% and 95.7% of S. Typhimurium and E. coli O2H6 biofilms when used at concentration 5% for 120 min while removed 89.7% of S. aureus biofilm at the same concentration and contact time. Additionally, sodium hypochlorite 5% for 120 min had a great efficacy and achieved 92.3% reduction of Staph. aureus biofilm meanwhile, removed 94.6% and 91% of S. Typhimurium and E. coli O2H6 biofilms. Copper sulphate wasn't a powerful enough disinfectant to eliminate the biofilms. It can be inferred that the inhibitory effect of the disinfectants against biofilms increases with the increase concentration and contact time with biofilms.