The reaction of azide with organotellurium(VI) halides Ph5TeBr and cis-(biphen)(2)TeF2 (biphen = 2,2'-biphenyldiyl) resulted in the formation and isolation of Ph5TeN3 (1) and cis-(biphen)(2)Te(N-3)(2) (2), which are the first tellurium(VI)-azide species. In addition to spectroscopic data, both crystal structures have been determined. Furthermore, the stability of possible Te(VI) species with higher azide contents PhxTe(N-3)(6-x) and MexTe(N-3)(6-x) as well as the syntheses and properties of their Ph/MexTeFy precursors was investigated, including the crystal structure determination of trans-Ph2TeF4 (3). Ab initio and density functional studies of all molecules regarding the structures and electronic populations were performed.