Gold being the most biocompatible metal nanoparticle has become an important biosynthesized drug to be studied in recent field of bioscience. The fungus Aspergillus fischeri has been isolated from fruit crop and thus exploited for the synthesis process. Synthesized GNPs were characterized by UV–visible spectroscopy showed absorption spectra in the range of 530–550 nm at different concentrations of HAuCl4. At the optimum reaction concentration of 1 mM HAuCl4, absorption peak was obtained at 543 nm. The GNPs have been further characterized by X-ray diffraction, FTIR, DLS and TEM analysis. The DLS graph showed that the particles were monodispersed. The TEM image showed the formation of spherical shaped GNPs in the range of 50 nm which was in accordance of the particle size analysis by DLS. The potential applications of the gold nanoparticles are yet to be explored and thus, we have conducted a time dependent comparative catalytic activity for methylene blue degradation of chemically synthesized and biosynthesized GNPs which showed biosynthesized ones are better catalysts than chemical ones.