High resolution infrared absorption cross sections of acetonitrile have been determined from spectra recorded in the 3μm spectral region using a Bruker IFS 125 HR Fourier transform spectrometer (FTS) and a multipass White cell. The eleven synthetic air-broadened acetonitrile spectra were recorded at a resolution of 0.015cm−1 (calculated as 0.9/MOPD (Maximum Optical Path Difference), the Bruker definition of resolution) over a range of different temperatures and pressures that are representative of conditions in the Earth's atmosphere (50–760Torr and 207–296K). Intensities were calibrated using infrared spectra recorded at the Pacific Northwest National Laboratory (PNNL). These new cross sections will enable satellite retrievals of acetonitrile in the 3μm region from atmospheric spectra recorded by satellite instruments, such as the ACE (Atmospheric Chemistry Experiment)-FTS.