The integrated band intensities at 296K of gaseous bromine nitrate (BrONO 2 ) in the spectral range 500–2000cm −1 have been measured using Fourier-transform absorption spectroscopy. The absorption spectra were calibrated to absolute absorption cross-sections using the integrated band strength of the ν 3 band around 803cm −1 (2.70±0.50×10 −17 cmmolecule −1 ) published previously. In this way, integrated band intensities were determined for the first time for the ν 1 band around 1709cm −1 (2.43±0.48×10 −17 cmmolecule −1 ), the ν 2 band around 1286cm −1 (2.99±0.60×10 −17 cmmolecule −1 ), the weak ν 4 /ν 8 bands between 720 and 760cm −1 (0.16±0.04×10 −17 cmmolecule −1 ) and the ν 5 band around 559cm −1 (1.02±0.20×10 −17 cmmolecule −1 ). The results are compared with the infrared band strengths of chlorine nitrate and with ab initio calculations.