The structure of a newly synthesized AgTlTeO 3 crystalline compound has been solved from single crystal X-ray diffraction data and refined to a final reliability factor R1=0.037. It was found having an orthorhombic Iba2 space group symmetry with unit cell parameters a=14.708(7) Å, b=10.745(6)Å, c=5.166(3)Å, Z=8. Its lattice is divided into separated AgTlTeO 3 sheets parallel to [010] which are formed by TeO 3 pyramids, TlO 4 disphenoids and AgO 6 octahedra sharing either corners or edges. At the same time, from the crystal chemistry point of view, it can be classified as a typical island-type compound made up from molecular-like [TeO 3 ] 2− ortho-anions weakly connected with Ag + and Tl + cations. The vibrational spectra and their interpretations complemented by the calculated elastic properties confirm this classification. The model-estimated piezoelectric constants allow characterizing AgTlTeO 3 as a strong pyroelectric structure.