We have studied photoluminescence from hexagonal InN/InGaN multiple quantum well structures grown on 3C‐SiC (001) substrates with an InGaN underlayer by plasma assisted molecular beam epitaxy. We have observed photoluminescence spectra of InN/InGaN MQWs with various well widths. The photoluminescence peak related to quantum wells was clearly observed even at room temperature and found to shift to higher energies with decreasing well width due to the quantum confinement effect. We also discuss the effect of the built‐in electric fields on the PL peak energy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)