The Solubility is an inherent property of any solid, liquid or gas. The solubility behaviour of drugs remains one of the most ambitious task in the formulation development. The solubility of drug dictates the ease with which pharmaceutical formulations can be obtained. Solid dispersion is an efficient mean of improving the drug solubility and from last many years it withstands with the objectives of producing improved dissolution rate and bioavailability of hydrophobic drugs. This review describes an overview of solid dispersions technology as a method of improving drug solubility which includes definitions of the various systems, preparation methods, various carriers and characterization methods of solid dispersions.