Ultrafine titanium dioxide nanowires of diameter ranging from 10 to 30 nm were successfully synthesized using a hydrothermal method. At first sodium titanate nanowires were prepared in a low-concentration sodium hydroxide solution with the assistance of ethylene glycol (EG). They were then converted to anatase titanium dioxide nanowires through acid washing and post-annealing. We conclude that EG increases the local alkalinity and the viscosity of the solution, therefore facilitating the growth of ultrafine nanowire. We propose that the synergy of oriented attachment (OA) and Ostwald ripening (OR) mechanisms are responsible for the growth of the nanowire. (c) 2012 Elsevier Ltd. All rights reserved.