This Chapter introduces the topic of vibrational spectroscopy in diagnosis and screening. A brief background to the key vibrational spectroscopic methods that are in current use is discussed. The historical dimension to the use of vobrational spectroscopy in diagnosis and screening is addressed. Finally, the recent trend in the use of mid-infrared, near-infrared, Raman and Terahertz spectroscopy in various areas of diagnosis and screening is presented.