Biocompatible gold nanoparticles were successfully synthesized by hibiscus plant leaf extract as a bioreactor. The prepared nanoparticles were evaluated using UV/Vis spectroscopy, Atomic Force Microscopy (AFM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction and Scanning Electron Microscopy (SEM) . The study also investigated the effect of the different gamma irradiation doses on the size and dispersion of the produced nanoparticles. In UV- Vis spectra, the peak of Au NPs' surface plasmon resonance (SPR) was detected as a single peak at 543 nm. The gamma irradiation induced a blue shift in the SPR peak, which indicates that it might be applied as affective factor for size control.  Physical as well as chemical compound of gold with extract was discovered using Fourier Transform Infrared (FT-IR) analysis. SEM results indicated that the nanoparticles size was in the range from (25.61 - 48.36) nm and most of particles appeared within the nanoscale with spherical and semi-spherical shapes, moreover, the irradiation process led to development in the shape and size of synthesized nanoparticles”