The formation of TiO2 powder from Ti(O-iC(3)H(7))(4) dissolved in supercritical isopropyl alcohol has been studied. Kinetic data were obtained in a temperature range of 531-568 K. A reaction mechanism has been proposed, based on a hydrolytic decomposition of Ti(O-iC(3)H(7))(4) by water produced in a catalytic dehydration of the isopropyl alcohol used as solvent and where the limiting steps are the decomposition reactions of the formed titanium hydroxides. In accordance with experimental results, such a mechanism leads to a first order kinetics relative to the precursor concentration. The activation energy was determined equal to 113+/-16 kJ . mol(-1), and an increase in the supercritical fluid density was found to decrease the overall reaction rate. The obtained results will be used to optimize the working of a continuous reactor producing submicronic TiO2 powder at a laboratory pilot scale.