Silicon is one of the most widespread elements in the natural world and, as such, this makes it a very interesting and useful element to study using NMR. Over the past few decades, a wide range of silicon-containing compounds have been investigated using both solid- and liquid-state NMR techniques. For example, siloxane polymers, which are extensively used in biomedical and cosmetic applications, have been extensively studied by NMR to understand their structure and individual building blocks. Similarly, the structure of silicates, zeolites and other materials have been studied by silicon NMR. Silicon NMR has been shown to be a powerful tool for the determination of active end groups, cross-linking moieties and polymer sequencing.