Ethylenediamine capped CuInSe2 nanoparticles were synthesized by wet chemical method at room temperature and hydrothermal method at 150 degrees C for 2 h at two different mole ratio of the capping agent. The effect of the synthesis method and ratio of the capping agent on the optical, structural, and morphology of the synthesized nanoparticles were analyzed. The optical property of the synthesized nanoparticles was estimated from the UV-Vis spectra and also from the emission spectra. The surface capping was confirmed through the FT-IR. Powder XRD analysis reveals that the nanoparticles exhibit wurtzite phase and the crystallinity increases while increasing the capping ratio and hydrothermally synthesized nanoparticles show higher crystallinity. Raman analysis shows that the hydrothermally synthesized samples exhibit B-2 (LO) mode. The surface morphology was modified depending on the synthesis method and capping agent ratio (i.e.) rod like and cube like morphology were obtained for the hydrothermally synthesized nanoparticles with 5 and 10 mol ratio of the capping agents respectively. (C) 2014 Elsevier Ltd. All rights reserved.