Turkey hemorrhagic enteritis virus (THEV) is one of Siadenoviruses associated with splenomegaly, bloody diarrhea and death in turkey poults. MDTCRP-19 cells are appropriate host for THEV propagation. The high yield of THEV nucleic acid was intended in molecular identification and genetic engineering, so RT-PCR hexon gene based was used to monitor THEV-A nucleic acid on MDTCRP-19 cells at two different multiplicity of infection (MOI) 10& 20 infectious virus particle (IVP) for 1-144 h post inoculation (P.I) that aid to detect the suitable time to harvest high yield of viral nucleic acid either from cell associated harvest or cell free harvest. The highest yield of viral nucleic acid was 3.4x10⁸   viral genome copy number (VGCN)/ μL  as cell associated harvest at 120 h P.I. with 20 MOI whereas; the maximum viral nucleic acid yield was 8.9x10⁷ VGCN /  μL  as cell associated harvest at 144 hr P.I. with 10 MOI. We concluded that the maximum yield of hexon gene for molecular biology studies was obtained at 120hr P.I. from cell associated harvest with 20 MOI.