ThPt2 crystallizes with unique type of structure (space group I4/mmm, a = 4.1565(1) Å, c = 14.3663(7) Å, Pearson symbol tI12), which belongs to the group of the close packed tetragonal structures. An analysis of the chemical bonding by the electron localizability approach reveals the formation of two-dimensional layered platinum anionic substructures interlinked by strongly polar bonds to Th. Measurements of magnetic susceptibility, electrical resistivity, and specific heat show ThPt2 to be diamagnetic with metallic type of electrical conductivity in good agreement with the calculated electronic structure (N(EF) = 0.9 states eV(-1) f.u.(-1)).