Gold nanoflowers were obtained by reducing chloroauric acid with tri-sodium citrate at a temperature of 95 degrees C. The UV-vis spectroscopy and scanning electron microscopy techniques were employed to monitor the growth of gold nanoflowers. The size and shape of the nanocrystallites of gold in the flowers were determined by X-ray diffraction and transmission electron microscopy methods. The 3-dimensional gold nanoflowers got fragmented into 2-dimensional petal-like nanostructures upon irradiation with 6-MeV electrons. The average size of crystallites of gold after electron beam irradiation was found to be similar to 10 nm. (C) 2010 Elsevier B. V. All rights reserved.