Abstract Seventy-six individual line intensities of the {ν 5 , 2ν 9 } and {ν 3 , ν 4 } bands of HNO 3 have been measured using high-resolution Fourier transform spectra recorded in the 450-1640 cm −1 spectral range. These intensities were then accurately reproduced using a model which takes explicitly into account both Fermi- and Coriolis-type resonances affecting the { v 5 = 1, v 9 = 2} and { v 3 = 1, v 4 = 1} interacting upper levels of HNO 3 . Finally, synthetic spectra (line positions and intensities) of the {ν 5 , 2ν 9 } (11 μm) and {ν 3 , ν 4 } (7.6 μm) bands of HNO 3 have been generated.