The book describes a study conducted in Bahri Locality. Forty five poultry farms were investigated and the prevalence was 11.1%. The prevalence rate was 6.67% in broilers farms and 4.45% in layers farms. The prevalence was 8.9% in the closed rearing system and 3.2% in the open system. A total of 92 bacterial isolates were obtained. The identified bacterial isolates were: Escherichia coli 59.8%, Proteus mirabilis 19.6%. Enterococcus faecalis 6.5%, Klebsiella pneumoniae subsp. ozaenae 5.4%, Salmonella sp. 3.3% and Staphylococcus aureus 5.4%. Ten E. coli isolates were selected randomly and and examined for their production of heat-stable enterotoxin using Suckling mouse test (SMT). Seven isolates (70%) gave positive results for SMT.