In this study, the emissions of volatile organic compounds (VOC), CH4, N2O and NH3 during composting non-source selected MSW, source selected organic fraction of municipal solid wastes (OFMSW) with wood chips as bulking agent (OF_wood) and source selected OFMSW with polyethylene (PE) tube as bulking agent (OF_tube) and the effect of bulking agent on these emissions have been systematically studied. Emission factors are provided (in kg compound Mg-1 dry matter): OF_tube (CH4: 0.0185 +/- 0.004; N2O: 0.0211 +/- 0.005; NH3: 0.612 +/- 0.269; VOC: 0.688 +/- 0.082) and MSW (CH4: 0.0549 +/- 0.0171; N2O: 0.032 +/- 0.015; NH3: 1.00 +/- 0.20; VOC: 1.05 +/- 0.18) present lower values than OF_wood (CH4: 1.27 +/- 0.09; N2O: 0.021 +/- 0.006; NH3: 4.34 +/- 2.79; VOC: 0.989 +/- 0.249). A detailed composition of VOC is also presented. Terpenes were the main emitted VOC family in all the wastes studied. Higher emissions of alpha and beta pinene were found during OF_wood composting processes. (C) 2014 Elsevier Ltd. All rights reserved.