Abstract The high-resolution infrared emission spectrum of potassium monofluoride has been recorded with a Fourier transform spectrometer. Over 900 vibration–rotation transitions, from the v = 1 → 0 to the v = 8 → 7 vibrational bands, have been assigned. Improved spectroscopic constants have been obtained for the KF ground electronic state by combining the infrared measurements with the existing microwave data.