Publisher Summary This chapter reviews the recent developments in the preparation and reactions of six-membered tellurium-containing heterocycles, in particular those related to heteroaromatic tellurium-containing cations. Organotellurium compounds display certain characteristic peculiarities of structure and reactivity in comparison with their sulfur and selenium analogs. These peculiarities are caused by low C–Te bond energy values in various types of compounds, the tendency of dicoordinate tellurium compounds to undergo oxidative addition reactions, enhanced halogenophilicity of the RTe- anions, high electrophilicity of the TeX3, (X = Hal) groups, and thermodynamic stability of derivatives of tetracoordinate tellurium. Such distinctive properties of organotellurium compounds often result in marked differences in the methods of preparation of tellurium-containing heterocycles in comparison with their sulfur and selenium analogs. A number of standard procedures developed for the synthesis of the latter fail to afford tellurium-containing heterocycles when based on similar organotellurium precursors. At the same time the distinctive features of organotellurium compounds make it possible to employ for the preparation of tellurium containing heterocycles reactions that are uncommon to the chemistry of organosulfur and organoselenium compounds.