Intramolecular vibrational redistribution is a fundamental phenomenon observed in polyatomic molecules when sufficiently excited vibrationally. In this paper, results mostly from the last two decades of research on this subject are summarized, obtained either from infrared spectroscopy with a resolution of as high as 10 À4 cm ÀI or, in a different approach, by using various pump-probe schemes with a temporal resolution from dozens of picoseconds to subpicoseconds.A A Makarov, A L Malinovsky, E A Ryabov