Clinical, bacteriological and postmortem investigations were applied on 30 newlyborm frezian calves suffering from pneumoenteritis in Bani-Mor friezian farm. The study revealed that E.Coli; Pasteurella; Staphylococci; Streptococci; Klebsiella ozaene; Citrobacter freundii; Enterobacter aerogenes and Enterobacter cloacae species were associated with this problem. Using invivo and invitro sensitivity tests, it was shown that Kanamycin injection in a dose of 5 mg/kg.b.wt. twice daily was very efficient in controlling such cases. The study revealed also that the use of Enterotube 11 Roche for the diagnosis of Enterobacteriaece infection was very helpful in reduc ing time and costs.