The present study deals with the infrared absorption spectrum of 1-bromo-3-fluoro-4-iodobenzene. The infrared absorption spectrum of 1-bromo-3-fluoro-4-iodobenzene has been recorded on Perkin Elmer spectrophotometer in the region 400-4000 cm-1 using KBr pellet technique. The analysis of spectrum has been made and the assignment of fundamental frequencies to various modes of vibration have been proposed by using these frequencies.