Monoclinic TeB4O8 was obtained in a Walker-type multianvil apparatus at 10 GPa and 1273 K from TeO2 and B2O3. It crystallizes isotypically to the compounds AnB4O8 (An=Th, U) in the space group C2/c (Z=4) with the lattice parameters a=15.6978(8) Å, b=4.2284(2) Å, c=7.4305(4) Å, β=114.78(1)°, and V=447.80(4) Å3. Further, it has been characterized via X-ray diffraction experiments and IR spectroscopy.