Perception of foods and beverages is mediated by the human senses, of which the five common senses play an important role. Sensory function at physiological and genetic levels is now understood in detail. This chapter provides details about the chemical senses, important for the perception of flavour. Chemical receptors for taste, smell and pain are widespread in the human body and are believed to have other functions, as in homeostasis and food intake regulation. Food perception is intertwined with the way humans select foods, food intake and learning of new food preferences. Sensory physiology undergoes changes and food preferences vary through life; perception of the sensory quality of foods is stable from early adolescence to old age.