A total of (160) samples of infected muscles and exudates were collected from (80) dead buffalo calves and (80) dead sheep, which showed clinical symptoms of blackleg and gas gangrene diseases. Samples were collected from different farms in Egypt. The bacteriological examination for clostridial gas gangrene organisms (C. chauvoei, C. septicum and C. perfringens type “A") yield 34 (21.3%) clostridial organisms. C. chauvoei, C. septicum C. and perfringens type “A" were obtained from buffalo calves with incidence of 8.8%, 6.2% and 11.3%, respectively .While the isolation rate from sheep was 3.8% , 5% and 7.5%, respectively .ELISA (enzyme linked immunosorbent assay), was in agreement with mouse protection test, and used for diagnosis of (C. chauvoei , C. septicunt and C. perfringens type “A"') from culture. Polymerase chain reaction assay (PCR) was a useful tool for direct and rapid detection of C. chauvoei , C. septicum and C. perfringens type “A" from clinical specimens (infected muscles with blackleg and gas gangrene). The 522 bp. amplification of C. chauvoei , 594 bp. amplification of C. septicum, while 1167bp. Amplification of C. perfringens type “A". The present study has shown that it is possible to amplify DNA specific to C. chauvoei and C. septicum in clinical materials as infected muscles and exudates in the same sample by PCR , an by one primer. But C. perfringens need another primer for rapid diagnosis in clinical materials by PCR .