This study was designed to detect the persistent infection with bovine viral diarrhea virus (PI- BVDV) among 114 bulls in Aswan Governorate. Sera samples were examined by ELISA and real time polymerase chain reaction (PCR) to detect BVDV antibodies and BVDV nucleic acid, respectively. The percent of infection was 23.7% (27/ 114) and 76.3% (87/ 114) were negative by ELISA technique, and 3.4% (3/ 87) for BVDV gene detection by real time PCR. Sensitivity of 89%and specificity of 96 % was reported using the commercially available ELISA kit for samples obtained from PI animals.