High-resolution infrared spectra of the stronga-type absorptions corresponding to the ν1(ν0∼ 1310.75 cm−1) and ν2(ν0= 821.9387 cm−1) bands of FNO2have been analyzed. The ν1line positions exhibited extensive perturbations as a result of three nearly degenerate vibrational states—ν1, ν3+ ν6, and ν5+ ν6—which interact through strong Coriolis coupling. The weak Coriolis interaction between ν2and ν6reported by Tanaka and Morino (1969,J. Mol. Spectrosc.32,436–448) manifested itself through changes in theb-axis constants of theν2= 1 state; nevertheless, over 1400 ν2transitions were fit with an rms error of 0.00066 cm−1using the standardA-reduced Hamiltonian. Line positions, assignments, and relative intensities for the dominant transitions in both bands have been established, although a comprehensive analysis of the perturbations requires a detailed understanding of the lower frequency vibrational states.