The purpose of writing this review on floating drug delivery systems was special focus on the principle mechanism of floatation to achieve gastric retention. Conventional oral dosage forms has short residence times & unpredictable gastric emptying time. The idea of gastric retention comes from the need to localize drugs at a specific region of gastrointestinal tract (GIT) such as stomach in the body. Many drugs get absorbed only in the upper intestinal tract, designing such molecules as once-daily formulations are exclusive for these molecules. Thus GI retention platforms had emerged. Gastroretentive drug delivery systems are designed to be retained in the stomach for a prolonged time. Gastroretentive drug delivery systems have potential for use as controlled release drug delivery system. The use of floating drug delivery system is one method to achieve prolonged gastric residence times, providing opportunity for both local & systemic drug action. Thus, gastroretention could help to provide greater availability of new products and consequently improved therapeutic activity and substantial benefits to patients.