In this paper, cathodoluminescence from InGaN/GaN single quantum wells grown on the facets of the GaN nano-pyramids has been quantitatively studied by Monte Carlo method. The influence of primary electron beam energy and the nanopyramid angle on generation of electron-hole pairs in individual parts of nanostructure has been studied by Monte Carlo simulations. The evolution of the GaN- and InGaN-related cathodoluminescence spectral lines with primary electron beam energy and angle of incidence has been assessed from the recombination rates in individual parts of the structure and compared with cathodoluminescence spectra measured at various beam energies. The possibility to determine the diffusion length of generated carriers in the structures like InGaN/GaN quantum wells using developed Monte Carlo simulator and CL measurements has been demonstrated. (C) 2012 Elsevier B. V. All rights reserved.