High-energy ball milling initiates a solid-state reaction in an equimolar mixture of TiO(2) and ZrO(2). The first stage of ball milling induced the transformation of anatase TiO(2) to high-pressure phase TiO(2) (II), isostructural with ZrTiO(4). The formation of solid solutions monoclinic ZrO(2)/TiO(2) and TiO(2) (II)/ZrO(2) was observed in the intermediate stage. Afterward, a nanosized ZrTiO(4) phase was formed in the milled product from the TiO(2) (II)/ZrO(2) solid solution. The sintering of the milled product at a temperature < 1100 degrees C was examined in situ by Raman spectroscopy. The full solid-state reaction toward ZrTiO(4) ceramic is completed at a temperature considerably lower than reported in the literature.