This study was done on three hundred samples (fecal samples collected from200 diarrheic calves, intestinal samples from90 dead calves, intestinal samples from10 slaughtered calves). These samples were collected from Beheira, Kalubyia, El – Fayoum and Kafr El – Sheikh Governorates in Egypt. These were subjected to bacteriological anaerobic examination, dermonecrotic reaction, mice neutralization test and multiplex PCR. Most of the examined samples revealed the presence of Clostridium perfringens Type A and its toxin alpha toxin. One hundred and fifty out of two hundred fecal samples (78.9%) revealed toxigenic isolates and typed as C. perfringens type A. Eighty five out of ninety (94.4%) intestinal samples of dead calves were toxigenic isolates. Typing of toxin detected 88.8% alpha toxin, 3.3% beta toxin and 2.2% epsilon toxin. The results of 10 samples of slaughtered calves revealed four toxigenic isolates and typed as alpha toxin .The toxin typing was confirmed by multiplex PCR. So it could be concluded that the main cause of enterotoxaemia in young calves is Clostridium perfringens Type A and its toxin (alpha toxin) which lead to sudden death in young calves.