Nano suspensions have gained great interest in the last decade as a formulation tool for poorly soluble drugs. By decreasing particle sizes nano suspensions enhance dissolution rate and bioavailability of the drug. Recently, nanoscale systems have received much interest as a way to resolve solubility issues because of their costeffectiveness and technical simplicity compared to liposomes and other colloidal drug carriers. They have also been used for drug targeting. Formulation of lipophillic drugs into nano suspensions improves their stability and also enhances their bioavailability significantly. Nano suspensions have unique advantages for which they have been utilized for the production of dosage forms suitable for administration through oral, parenteral, ocular and pulmonary routes. Nano suspensions can be manufactured using the ‘Top Down’ or ‘Bottom’s Up’ technology and employ a variety of components including surfactants for stability purposes and polymers for sustained release of drug in certain formulations. This paper reviews recent patents,

methods  of preparation and marketed products with their importance or status, novel researches and characterization implemented till date to overcome the challenges in poorly water soluble drugs.