A total of 200 intestinal content and cloaca swabs were collected from a 80 recently weaned rabbit and 120 adult freshly dead and sacrificed rabbits suffered from diarrhoea, addition 20 cloaca swab were collected from apparently healthy rabbits. These samples were collected from privately owned rabbitaries at EL- Minia and Assiut Province for P.M and bacteriological examination. The clinical examination and postmortem lesions revealed to depression, anorexia, exhaustion, rough coat, profuse Watery diarrhoea, catarrhal enteritis, peticheal haemorrhages on the internal organs and enlargement of liver and spleen. The bacteriological examination from all examined samples revealed that the highest percentage of E.coli (80%) followed by P. mirabilis (27.3%), Enterobacter cloacae (22.3%) Akaligenes (16.4%), Klebsiella (13.6%) Citrobacter (8%) while Salmonella typhimarium was (5.5%) and Salmonella enteritidis was (8.2%), while could not isolate from apparent healthy rabbits. The incidence percentage of E.coli in summer was (76.5%) while in winter was (23.5%) and Salmonella typhmarium and Salmonella enteritidis were (75%) and (77.8%) in summer while were (25%) and (22.2%) in winter respectively. The most common serotypes of E.coli in order of frequency were Oss/K59 (Bs) 15 ) 8.8% ) 5.9% ) 105 0;( B) 15 (8.8%); 09/B ) 12 و[ 7.1% ( 012g:K67,(B12 10 ( ) ورK7:026 ;( B) 8(4.7%); 07g/Kg0 (B) 7 (4.1%) and 90 untypable. For virulence assay of E.coli showed that 82.3% of E.coli isolates were Congo red positive (+ve CR) and 17.6% were Congo red negative (-ve CR), while haemolytic activity revealed that (52.9%) of E.coli isolates were positive for haemolytic activity from diarrhoea rabbits, while was (100%) negative haemolytic activity from apparently healthy rabbits. Results of experimental infection of the susceptible animals it is showed that the isolated strains were pathogenic with mortality rates ranging from 60% to 100% and the clinical symptoms and post-mortem pictures of inoculated rabbits are similarly that showing in examined diarrhoea rabbits in our work. Sensitivity test for the isolates revealed that E.coli strains were highly resistant to Ampicillin, Erythromycin, Streptomycin, Chloramephenical and Amoxycillin, while it is highly sensitive to Enrofloxacin, Gentamycin and Colistine sulphate. Salmonella isolates were more susceptible to Ampicillin, Neomycin sulphate; Gentamycin and Enerofloxacin while are resistant to Erythromycin, Streptomycin and Amoxycillin.