Nanodispersion of agglomerated TiO2 powders has been performed by microbead milling and its effect on photovoltaic performance has been investigated with dye-sensitized solar cell. Plasma-treated 30 µm-diameter zirconia beads are used to disperse commercially available Degussa P25 TiO2 in ethanolic medium. Particle size distribution, surface area, film morphology, porosity, transmittance and haze are investigated with different milling speed of 30 Hz and 45 Hz and milling time of 30 min and 90 min. After microbead milling, average particle size is reduced with narrow size distribution, as a result surface area is increased. A slight phase transformation from anatase to rutile is observed during microbead milling. Film porosity is significantly changed from 76% to about 51% after microbead milling due to highly dispersed nature. Microbead milling has also influence on optical property, where transmittance increases and haze decreases with increasing milling speed and/or milling time. Compared with photovoltaic performance of dye-sensitized solar cell based on the as-received P25, overall conversion efficiency with the aperture-masked cell is substantially improved from 4.46% to 6.42% after microbead milling at 30 Hz for 90 min, corresponding to 44% increment, which is mainly due to a noticeable increase in photocurrent density, associated with highly dispersed characteristics by microbead milling.