Titanium (Ti) is one of the most promising biomaterial for biomedical devices due to its high corrosion resistance and specific combination of strength and biocompatibility. Titanium dioxide (TiO2) nanostructures are obtained by electrochemical anodization of Ti foils under self-organization condition; anodization parameters such as anodization time, voltage, temperature and most important electrolyte composition are critical for the resulting morphology. Nanostructures are grown in ethylene glycol (EG) based electrolytes and we evaluated the influence of the water content, as no nanostructures are formed in the electrolyte without water addition, and with increasing water content, either nanopores or nanotubes are obtained (depending also on the applied potential and anodization time). The increase in water content in the electrolyte enables the slow transition from nanopores to nanotubes, which occurs by a pore-wall splitting mechanism. From the current results, one can conclude that the water in the electrolyte has a definite effect on the type of nanostructures obtained by electrochemical anodization in organic electrolytes. This current investigation of effect of water in EG based electrolytes is useful for obtaining the desired morphology of the nanostructures (diameter, length, open-top morphology) for specific bioapplications.