There is an increasing need for new techniques for the understanding, monitoring and the control of batch processes. Spectroscopy is now becoming established as a means of obtaining real-time, high-quality chemical information at frequent time intervals and across a wide range of industrial applications. In this article, the role of spectroscopy for batch process monitoring is discussed in terms of both current and potential advances. The emphasis is on how to handle the measured data to extract maximum information for improved process performance and efficiency. In particular, the use of spectroscopy for statistical process monitoring is detailed and considered as complementary to the use of engineering process data. A case study of the ultra violet-visible monitoring of a first-order biochemical conversion reaction is described, as well as the advantages of spectroscopy for process fault detection and diagnosis. Future prospects for the use of on-line spectroscopy are also discussed.