Nasal route is alternative to parenteral therapy and also useful for long term therapy. Nasal route is non invasive, widely used for the local treatment may also be used for systemic therapy as drug directly goes in systemic circulation. In this article an overview of intranasal drug delivery with its various aspects like factors affecting nasal absorption are discussed. 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 disease, Alzheimer’s disease) because it requires rapid and/or specific targeting of drugs to the brain. However, when considering nasal delivery devices and mechanisms, it is important to keep in mind that the prime purpose of the nasal airway is to protect the delicate lungs from hazardous exposures, not to serve as a delivery route for drugs and vaccines. New and emerging delivery technologies and devices with emphasis on BiDirectional™ delivery, a novel concept for nasal delivery that can be adapted to a variety of dispersion technologies, are described in more depth.