The infrared absorption spectrum of ClONO2 has been recorded between 500 and 1600 cm-1 at temperatures between 188 K and 222 K and resolutions of up to 0.004 cm-1. The infrared absorption cross sections were determined for the entire &ngr;2 band between 1260 and 1320 cm-1. The cross sections (with 0.025 cm-1 resolution) for the central Q branch absorption maximum at 1292.68 cm-1 are (in 10-18 cm2 molecule-1) 3.12¿0.06 at 201 K, 3.45¿0.15 at 211 K, and 3.31¿0.06 at 222 K. The influence of resolution on the cross section of the Q branch maximum is small only for resolutions between 0.025 and 0.100 cm-1. In the P and R branches, the cross sections are important for the determination of stratospheric ClONO2 concentrations from atmospheric infrared absorption spectra and for modeling atmospheric transmission in the spectral region around 1292 cm-1. ¿ American Geophysical Union 1994