Abstract A reverse microemulsion-mediated hydrothermal route has been employed to synthesize photocatalytic titanium dioxide (TiO 2) powders. Nano-crystalline monophasic anatase TiO 2 powders were successfully prepared when the microemulsion-derived precursors were hydrothermally treated. The advantage of using this microemulsion mediated hydrothermal route is the significant reduction in reaction time and temperatures as compared with the conventional hydrothermal process. The oil/water emulsion ratio significantly affected the particle sizes of the obtained TiO 2 powders. The specific surface area of TiO 2 powders was increased with the oil/water ratio, thereby leading to enhanced photocatalytic activity of TiO 2 powders. As the hydrothermal temperature was elevated, the morphology of the TiO 2 particles changed from a rod-like shape into a polyhedral shape. The variation in microstructures decreased the specific surface area of the TiO 2 powders and lowered the photocatalytic activity.