A total of 100 samples were collected (75 samples from diseased broiler chickens and 25 samples from recently dead broiler chickens). The samples were examined bacteriological, fifty two isolates of E.coli (52%) and seven isolates of Salmonellae (7%) were found. ten random samples of E.coli were sero grouped where five were E.coli O78, two O157 and untyped and seven isolates of salmonellae were serotyped where three S.Enteritidis, one S.Charity, one S.Remiremont and two untyped . Antibacterial activity of five medicinal plant oils from Eucalyptus, Mint, Cinnamon, Garlic and Thyme were evaluated against the isolated strains using micro-titer plate to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for these oils. MIC results proved that for Mint, Cinnamon, and Garlic oils were ranged from 5-5120 μg/ml, for Eucalyptus 20-5120 μg/ml and for Thyme 5-2560 μg/ml. While results of MBC of Thyme and Cinnamon oils were ranged from 10-2560 μg/ml. but MBC of Eucalyptus ranged from 40-5120 μg, MBC of Mint and Garlic oils were ranged from 5-2560μg |ml, 20-2560μg |ml respectively.