In the present work we report that TiO2 nanotubes (TiNT) can be formed by electrochemical anodization of titanium in an 2-propanol/water + 0.14 M NH4F. The effects of water contents, time of anodization and the potential on the growth behavior of the TiNT were studied. The optimum solvent composition water / 2-propanol was found 16 vol% water. At this % the reaction between solvated electrons and hydrogen ions, which was considered as a possible rate determine step, is kinetically controlled. The titania nanotubes obtained under the optimum conditions have heights up to 1800 nm and inner diameters around 90 nm. Increasing the potential beyond 20 V did not show better nanotubes. This was attributed to the fast reactions under the high field led to disordering equilibrium of the controlling reactions.