Nanotechnology holds immense promise for transforming the realm of pharmaceutical science, analogous to the groundbreaking impacts of biotechnology and genetic engineering. Nanofillers, characterized by their minute particle sizes ranging from 1 to 100 nanometers, have long been in existence and encompass materials such as precipitated calcium carbonate, synthetic silicas, and carbon blacks. The careful selection of nanofillers, taking into consideration their unique physical and dimensional characteristics, allows for customization to meet specific application needs. Due to their nanoscale dimensions, fillers exhibit significantly enhanced properties compared to pure polymers, including heightened modulus and strength, exceptional barrier characteristics, improved resistance to solvents and heat, and reduced flammability. Among the various nanofillers, carbon nanotubes (CNTs) have emerged as a recent and remarkable filler, extensively utilized due to their exceptional attributes. Nanofillers exhibit remarkable thermal, mechanical, and electrical properties that surpass those of traditional materials, making them highly advantageous. Currently, nanofillers find extensive use in various fields, including rigid containers, automotive components, packaging films, industrial components, and medical devices. Within this chapter, we explore the diverse pharmaceutical applications of nanofillers across various domains, including disease diagnosis, prevention, and treatment.