Intranasal drug delivery system provide distinct advantage over conventional drug delivery system for a drug that is pharmacokenetically or biologically unstable. Major concern for treatment of central nervous system diseases are law concentration of therapeutically active molecule within brain as blood brain barrier is creating obstacle, where intranasal drug delivery provides direct transport of therapeutically active moiety into brain via olfactory or trigeminal pathway. Nasal mucosa provides distinct advantage like improved bioavailability, law dose and quick onset of action and high patient compliance, major disadvantage is residence time of drug and irreversible entrapment of drug. This article provides anatomical and physiological information about nasal route and various factors. Article discusses various types of nanoparticles used intranasally and moreover article also emphasizes patents, formulation under development and some legal aspects regarding nano medicine.