Hydrogels are materials that can hold significant volumes of water, which makes them of great value for many purposes, among them drug delivery and wound healing. The particles added to these hydrogels enable improvement of mechanical strength and sensitivity to environmental change and increase in a number of functions, including the creation of antibacterial or healing functionalities. This chapter explains the methods which can be used to prepare these nanocomposite hydrogels and the characterizations techniques to inspect their structural properties, mechanical properties, and other key properties. Thus, the aim is to achieve a very definite understanding of what exactly they are, how they are prepared and why and how they are of importance in the medical field.