This study was conducted to evaluatethe degree of biosecurity level with especial reference to Salmonella Spp as an example to explain the expected causes and risk factors that leads to spread them in poultry flocks in Egypt then studied farms evaluated for the sensitivity of Salmonella isolates to the most common disinfectants used in Egypt.About 300 samples (100 cloacal swabs, 100 liver and intestinal samples,100 litter samples) were collected from 10 broiler farms with different age (at 0 old day, one week,2,4 and 6 weeks of age)then the samples were investigated for Salmonella Sppand subsequently identified based on biochemical and serological tests.The obtained results showed that 35 Salmonella species were isolated from 10 broiler poultry houses (25%);(6%) and (4%) from cloacal swab;liver and litter, respectively. Average prevalence of Salmonella spp. was 11.33 % in open broiler houses whether raised Cobb, Ross or Sasso breeds. Salmonella Typhimurium, S. enteritidisand S. Kentuckywerethe most serovars out of the 35 detected isolates.There was
great statistical significant difference in the sensitivity of Salmonella isolates to the most commo disinfectants (P<0.05)asVerkon- S® achieved 3 log reduction, after 5-minute,Formalin and Phenique were achieved 3 log reductions against S. entriditisafter one-minute Aldekol Des- Gda® achieved one log reduction after one minute, TH4®,Biosentry® 904 and Iodophoreachieved 2 log reductions after 5 minutes.