A comprehensive theoretical model for InGaN core/multishell nanowire (CMS NW) light emitting diodes (LEDs) has been developed that accurately predicts both electrical and optical properties of CMS NW structures. Using the model, the electron and hole injection in a CMS NW device was studied, showing that the InGaN quantum well (QW) serves as a high electron mobility channel for electron injection while the poor hole conductivity in the p-GaN outer layer confines hole injection to an area directly below the p-contact. Light generation in the CMS NW was found to occur only directly below the p-contact in the InGaN QW as a result of the isolated hole injection. The model was found to accurately predict the optical emission of the CMS NWs for both changes in thickness and Indium composition of the InGaN QW when compared to experimental values from the literature. Piezoelectric effects were not found to play a significant role in the CMS NWs, suggesting that alloy broadening and excitonic emission are the dominant role in determining the FWHM of the CMS NW emission.