Due to its interesting chemical, physical, and biological properties, boron nitride has received considerable attention by the scientific and technological communities. However, there is a strong dependency of its structural quality and compatibility in different host systems, regarding its potential applications. The use of these different nanostructures involves several challenges due to their low dispersibility in water and organic solvents; thus, its chemical modification is an important step that gives them specificity. Therefore, the ability to control their surface (physically or chemically) is essential for exploring and building blocks in the nanoengineering of supramolecular structures. In this chapter, we report different boron nitride functionalization processes, as well as their important uses as adjuvants in vaccines, brachytherapy, or drug delivery. Besides some important theoretical studies that have demonstrated the different functionalization possibilities for use in nanomedicine, are also reported.