This chapter is focused on nondestructive analytical methods based on vibrational spectroscopy. Following the tenets of process analytical chemistry, these analytical methods may monitor a manufacturing process as it occurs providing information on critical product quality attributes that is then used to control the process and achieve the expected product quality. The application of these principles to the improvement of pharmaceutical manufacturing has been termed process analytical technology, and is currently transforming the manner in which pharmaceutical processes are evaluated by regulatory agencies.Nondestructive methods may also be developed for use in a laboratory setting providing information after the product is manufactured. In both settings, the use of hazardous substances and consumption of materials is avoided in the analyses performed. These nondestructive methods present several advantages in comparison to the current laboratory‐based methods that require the use of reagents and transformation to clear solutions. The use of nondestructive testing often permits the simultaneous determination of chemical and physical properties in the materials analyzed. In some cases spectral changes may also be correlated with sensorial evaluation of product properties. These advantages have become a reality in industrial settings. Examples from the biodiesel, dairy, pharmaceutical, and polymer industries are discussed.