Theranostic is a specialized clinical disease management that renders highly specific, non-invasive diagnosis and therapeutic approach within the ambits of patient physiology, drug compliance and safety. Nanomedicine helped to transform this concept into clinical reality enabling rapid assessment and adjustment of treatments to be target specific, enabling controlled drug release, circulation and bioavailability, and interestingly provide platforms for the online-realtime imaging of disease site. This review paper is intended to briefly emphasize the mediating role and importance of multifunctional nanoparticles in the development of rapid, sensitive and effective diagnostic and therapeutic tools for the deadliest diseases. In this, we discussed the role of nanotechnology and nanomaterials for the diseases like cancer, HIV-AIDS, tuberculosis, diabetes, brain and cardiovascular related diseasesetc, as the therapeutic administration becomes easier in early stages and has been the most important component of advance prognosis.