The structure of Ag0.167TiS2 has been determined at several temperatures from time-of-flight neutron powder diffraction data. At 305 K, Ag0.167TiS2 is a stage-II complex which belongs to the space groupP3-m1, witha = 3.4161(4)Åandc = 12.100(2)Å. When the temperature is lowered to 13 K, the lattice parameters decrease, but no phase change or superlattice formation is observed. Upon heating to 1123 K, this compound transforms to a stage-I structure belonging to the space groupP3-m1, witha = 3.4676(1)Åandc = 6.2247(4)Å. No further phase changes are observed when the temperature is raised to 1323 K. When this compound is slowly cooled to ambient temperature from 1323 K, it transforms quantitatively to the original stage-II structure. The Rietveld refinements of Ag0.167TiS2 at six temperatures are presented and discussed.