The objective of this study was to use the molecular methods for genotyping the Egyptian isolates of bovine viral diarrhea virus (BVDV) from purified milk somatic cells (PMSC) samples using restriction enzyme (RE)-Pst1 after amplification the viral RNAs at 5`untranslated region (5`UTR) by reverse transcription-polymerase chain reaction (RT-PCR). A purified and biological active RNAs were extracted from 29 inoculated isolates on Madin-Daby bovine kidney (MDBK) cells tested against latent infection with BVDV. By using UV spectrophotometer at wavelength 260 nm, the optical density (OD) of the extracted RNAs was an average 0.8-0.9. A primer sequence within 5`UTR flanked the region (108-128th nucleotide, nt, as upstream and 395-375th nt as downstream) and Taq DNA polymerase enzyme were used to amplify and gave highly specific bands at 288 bp. The 29 isolates were clearly identified by ethidium bromide staining of the amplified DNA specific bands at (288 bp) in the gel. The RT-PCR products of the isolates in this study were digested with RE-Pst1 and gave 2 sharp bands at molecular weight 230 and 58 bp. A positive control, NADL strain, represented genotype I was included allover this study. In conclusion, the single RE digestion of RT-PCR-amplified 5`UTR products may be a quick and easy method for identification of BVDV genotype. Understanding the molecular epidemiology and molecular biology of BVDV is an important milestone. Improved diagnostic and control strategies are essential to reduce losses inflected by BVDVs