Our work about exo-2,3-epoxynorbornane was published on ChemPhysChem, 2015, 16, 2609–2614. We showed a study of exo-2,3-epoxynorbornane in the gas phase by pulsed jet Fourier transform microwave spectroscopy in the 4–18 GHz region. Six isotopologues were observed and characterized in their natural abundance. The experimental substitution and effective structures were obtained. Comparison with the structure of norbornane shows significant differences in several bond lengths and valence angles upon introduction of the epoxy group. All the work is supported by quantum chemical calculations.