Computerized data bases of IR spectra are among the oldest spectroscopic data bases to have been made available and used by the scientific community. Their use has not, how-ever, lived up to expectations or been as extensive as that of other related tools, such as mass spectral data bases. The purpose of this paper is to describe some of the computer search systems that work with these collections of spectral data. The history of the major collections of condensed IR spectra will be outlined, and more recent work directed towards the compilation of collections of condensed-phase and gas-phase spectra, with or without the use of Fourier transform techniques, will also be summarized. © 1979 Oxford University Press.