Clostridium perfringens is a ubiquitous and versatile pathogenic bacterium and is implicated in the etiology of the poultry diseases necrotic enteritis (NE) .In this work, four outbreaks of necrotic enteritis were investigated in broiler farms in the AL-Hasa governorate, KSA. The clinically affected birds showed moderate to severe depression, diarrhoea and death. At necropsy, the birds generally showed good bodily conditions, but severely dehydrated. The striking gross morbid lesions were located at small intestine , where it was found markedly dilated with patches of multifocal hemorrhage in the inner wall. Intestinal impression smears showed a plenty of Gram positive bacilli. Eleven Clostridial isolates were characterized phenotypically and biochemically. All isolates exhibited characteristics of Clostridium perfringens. Culture supernatants from all isolates were toxigenic for mice. ELISA and mouse neutralization test revealed the detection of alpha toxin from all isolates. All the Eleven isolates proved the alpha toxin producing strains of C. perfringens when they were subjected to alpha toxin specific PCR. The antimicrobial susceptibility test showed that All isolates were susceptible to Amoxicillin, Amoxicillin- Clavulanic acid, Cefoxtin, Cephalexin , and Metronidazol. On the other hand, all isolates were resistant to Sulfaquinoxalin (100%), 10 isolates (90.4%) to Erythromycin, cephalexin and 4 (36.3% )isolates were resistant to Oxytetracyclin. In conclusion, alpha toxin specific PCR is highly useful for detection of toxigenic strains of Clostridium perfringens in poultry, A continuous monitoring of the virulence factors and the antimicrobial susceptibility profile of C. perfringens from animal origin, particularly, poultry are necessary for a better prevention and treatment of the necrotic enteritis in avian and new control and prevention strategies are needed.