The gas-phase infrared spectrum of cis-1-bromo-2-fluoroethene has been studied at low resolution in the range 200–6500cm− 1, leading to a complete assignment of the fundamentals, except the lowest vibrational mode ν9 predicted at 167cm− 1. The remaining vibrational structure has been mainly interpreted in terms of first overtone or two quanta combination bands. Isotopic 79/81Br shift has been observed only in the ν8 fundamental. ...