P OTATO VIRUS Y (PVY) is one of the most destructive aphid transmitted pathogen to potato plants worldwide. In Egypt, PVY infection causing about 80% reduction the global yield of potato. The objective of this study was to characterize Potato virus Y (PVY-EG) infecting potato plants, based on biological, serological and molecular properties. Naturally infected potato plants by PVY gave positive reaction with PVY-polyclonal antibodies using DAS-ELISA for virus identification. PVY has a higher stability at 45 h (Longevity), 66°C at 10 min (TIP) at 10-6 (DEP), revealing presence of cytoplasmic and crystalline inclusion bodies of the epidermal strips from infected Datura metel (diagnostic host) leaves at 12 days post PVY inoculation. The PVY has UV-spectra at λ 235 and at λ 257 nm. PVY yield was 1.25/100 g leaf tissues and 260/280 more than 1 (it was 1.6). The viral particles were rod flexible (helical symmetry) of 11 x 570 nm, with obvious immunogenicity that represented by 1:1024 titer of antibodies. The cDNA fragment of CP gene was 610 bp. Sequence analysis revealed that PVY isolate showed 93-99% similarity with other worldwide PVY isolates.