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 of 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-determining 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.