Chemoreception, an ability to perceive specific chemical stimuli, is one of the most evolutionarily ancient forms of interaction between living organisms and their environment. Chemoreception systems are found in organisms belonging to all biological kingdoms. In higher multicellular animals, chemoreception (along with photo- and mechanoreception) underlies the functioning of five traditional senses. Insects have developed a peculiar and one of the most sophisticated chemoreception systems, which exploits at least three receptor superfamilies providing perception of smell and taste, as well as chemical communication in these animals. The enormous diversity of physiologically relevant compounds in the environment has given rise to a wide-ranging repertoire of chemoreceptors of various specificities. Thus, in insects, they are represented by several structurally and functionally distinct protein classes and are encoded by hundreds of genes. In the current review, we briefly characterize the insect chemoreception system by describing the main groups of receptors that constitute it and putting emphasis on the peculiar architecture and mechanisms of functioning possessed by these molecules.