The prediction of IR spectra of organic compounds containing carbon, n
itrogen, oxygen and halogen atoms, from a spectroscopic database, is o
utlined. Structure similarity searches are performed to determine appr
opriate neighbours that are used for the prediction of the unknown mol
ecule. The reliability and performance of the system was tested by ''l
eave one out'' procedure. In about 96% of ail cases the system gave re
liable answers.