Epornitics of duck pasteurellosis were diagnosed in duck farms at El-Wady El-Gadeed during 1985-1987. Pasteurella multocida (5:A and 2:D) and Pasteurella anatipestifer were isolated from different ages of ducks. Pasteurella anatipestifer was identified biochemically and biologically. Pasteurella multocida isolates were identified, biochemically, biologically and serologically. Succeful reproduction of the disease was conducted with Past eurella multocida and Pasteurella anatipestifer. pasteurella anati pestifer infection resulted in serofibrinous inflammation in epicard ium, pericardium and liver capsule. Pasteurella multocida infected birds showed haemorrhagic lesions, hepatic necrosis and interstitial pneumonia.