These studies aimed at providing information on floating drug delivery systems. By studying various international, and national journals, and reviewing articles on floating drug delivery systems as well as gastro retentive drug delivery systems, the authors congregated the information on floating drug delivery systems. In developing various drug delivery systems, gastro retentive drug delivery systems (GRDDS) has got an important place, as the conventional oral dosage forms have numerous problems such as gastric emptying time, enzymatic activity, and gastric pH changes. To overcome these problems, control drug delivery systems have been developed in the recent drug development approaches. Both effervescent and non-effervescent systems are the two main gastro retentive systems. Effervescent forms were developed using two systems, such as raft formation and gas generating systems. For gas generating systems, the most extensively used agent is sodium bicarbonate and, in some cases, ratios of sodium bicarbonate and citric acid. Developing an efficient gastro-retentive formulation is a real challenge, and the drug delivery system should remain for a sufficient time in the stomach. Various techniques and approaches have been employed to develop gastro-retentive dosage forms, and floating drug delivery systems (FDDS) has emerged as promising gastro-retentive drug delivery system. The currently available polymer-mediated non-effervescent and effervescent FDDS systems, which are designed based on the delayed gastric emptying and buoyancy principle, appear to be an effective and rational approach to modifying the controlled oral drug delivery.