Photocatalytic performance of a hydrothermally synthesized pure anatase TiO
2
with 8mm average crystalline size for decomposition of Reactive Red 141 was examined by investigating the effects of UV-light irradiation time, irradiation power, amount of TiO
2
and initial dye concentration. Change in the UV absorbance of the dye during irradiation was monitored. One wt.% TiO
2
in 30 mg/l Reactive Red 141 aqueous solution was found adequate for complete decolorization in 70 min at 770 W/m
2
irradiation power. It was realized that, compared to Degussa P-25, the synthesized nano-TiO
2
can be repeatedly used as a new catalyst. The results also proved that Reactive Red 141 is decomposed catalytically due to the pseudo first-order reaction kinetics.