During 2004-2005, out of 25 lambs up to 10 weeks old which died suddenly, 13 Clostriduim sordellii were isolated. The post mortem findings varied. losses have been sporadic in some farms in Kaft el-sheikh governorate and recorded in all age of lambs. Also, 61 fecal samples of diarrhetic lambs at three different age group, were examined bacteriologically for the presence of clostridium with special emphasis on C. sordellii, the isolation rate of C. sordellii was higher in all age groups (24.6,8.3 and 5%) that other Clostridium species. C. perfrongens, C. sporogenes, and C. bifermentans were isolated and identified in a different percentage. In vitro, the sensitivity of C. sordellii isolates to different chemotherapeutic agents was determined. Results of this study indicateds that Clostriduim sordellii should be considered when investigating the cause of sudden death in lambs.