The focus of present work is on the influence of source reagents on the properties of CuInSe2 (CISe) photoabsorber powders prepared by microwave assisted synthesis in triethylene glycol and polyethylene glycol. The CISe powders prepared were investigated by the X-ray diffraction (XRD) technique, scanning electron microscopy (SEM) equipped with an EDS analyzer and MicroRaman spectroscopy to control the composition, structure and morphology of the synthesized powders. It was found that the microwave assisted polyol method is useful for the synthesis of CISe nanopowders. Synthesis with metallic In and Cu precursors resulted in the residue of unreacted indium in the products of reaction and deviation of the resulting CISe powder composition from the stoichiometry. On the other hand, soluble salts of In(III) and Cu(I) used as source reagents lead to practically stoichiometrical CISe powder to be prepared. Chalcopyrite structure of the prepared CISe powder and polynanocrystalline morphology were confirmed by the XRD, SEM, EDS and Raman techniques. The purest CISe powder was synthesized from CuCl, In(OOCCH3)3 and Se source reagents. The average size of the prepared CISe powder grains depends on the average molecular weight of the solvent (polyol). Polyethylene glycol 600 used as the reaction solvent gives a practically uniform polycrystalline CISe powder with an average size of crystals around 80 nm