Present work reports a new method for one pot synthesis of nanosize cuprous oxide (Cu2O). In this method, the synthesis of nanocrystalline Cu2O was carried out using benzyl alcohol as a solvent and copper acetate as a precursor under microwave irradiation. In this protocol, benzyl alcohol played a multiple role such as solvent, reagent and stabiliser eliminating the need of any other extraneous additives. The protocol enables synthesis of nanosize cuprous oxide within a short span of few minutes and without calcinations. The prepared nanosize Cu2O was characterised with the help of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDS) and UV-vis absorption spectroscopy. The results showed that the size of Cu2O particles was in the nano region. The particles were well crystalline and essentially pure. This is one of the facile and environment friendly protocols for synthesis of nanosize cuprous oxide. (C) 2012 Elsevier B.V. All rights reserved.