Nanocarrier systems have gained popularity for drug delivery and diagnostic purposes, offering targeted and site-specific transport of highly efficacious medications. These systems connect biological and physical sciences, allowing for the treatment of various diseases and disorders. They can avoid severe side effects, improve target specificity, and reduce doses. Modifying carrier properties, such as targeted delivery, regulated distribution, and shielding from biological milieus, can further enhance their benefits. Several targeted nanocarrier systems such as nano-crystals, lipid nanoparticles (NPs), PEGylated polymeric nanocarriers, nanofibers, quantum dots, liposomes, dendrimers, micelles, protein-based nanoparticles, and metal-based nanoparticles are well explored for their benefits over conventional drug delivery systems. This chapter specifically highlights the different types of PEGylated nanocarriers and their uses in targeted drug delivery.