<b>Nasal Drug Delivery System A Review</b> The use of the nasal route for the delivery of challenging drugs such as small polar molecules, vaccines, hormones, peptides and proteins has created much interest in nowadays. Due to the high permeability, high vasculature, low enzymatic environment of nasal cavity and avoidance of hepatic first pass metabolism are well suitable for Systemic delivery of drug molecule via nose Many drug delivery devices for nasal application of liquid, semisolid and solid formulation are investigated to deliver the drugs to the treat most crisis CNS diseases i.e., Parkinson’s dis ease, Alzheimer’s disease because it requires rapid and or specific targeting of drugs to the brain. It is well suitable for the delivery of biotechnological products like proteins, peptides, hormones, DNA plasmids for DNA vaccines to give enhanced bioavailability. This review sets out to discuss some factors affecting nasal absorption, bioavailability barriers, strategies to improve nasal absorption, new developments in nasal dosage form design and applications of nasal drug delivery system. Bioavailability, Patient Compliance, First pass effect, absorption Enhancers 572-579 Issue-5 Volume-5 Aarti C. Nangare | Sujit Kakade | Ashok Bhosale