Sweetness is always associated with emotive value judgments of what are thought to be liking, appreciation, attention, and reward. It has been shown that the ability to experience the sensation of sweetness is an inborn quality. Of the four basic taste sensations that can be experienced by man in chemoreception, sweetness has been studied the most exhaustively as to chemical structure‐taste relationships. Thus, in the last few decades a very large number of structurally unrelated compounds have been synthesized and evaluated for sweetness. This review summarizes the history of the discovery of sweeteners, the various receptor theories developed in the course of time, the transduction of taste, the neurophysiological mechanisms involved in sweet taste perception, the various sweet taste receptor sites, and the structure‐activity relations (SAR) explored so far. The authors subsequently discuss in detail the following classes of sweeteners: carbohydrates, nitro‐anilines, benzamides, amino acids, dipeptides, dihydrochalcones, flavonoids, isocoumarins, sulfamates, oximes, saccharins, acesulfames, urea derivatives, sesquiterpenes, diterpenes, triterpenes, and some sweet substances isolated from plants. On the basis of the present knowledge it can be concluded that there is more than one type of sweet taste receptor. It is expected that the rapid progress in molecular biology and X‐ray crystallography and the use of molecular modeling based on computer graphics will afford a deeper insight into the sweet taste perception mechanism in the near future.