Commercial anatase containing an appreciable amount of sulphur has been treated for sulphur removal by calcination at increasing temperatures or soaking with aqueous NaOH solutions. It has been found that both methods are active for sulphur removal, but the first one also leads to a sharp sintering of the titania particles. On the other hand, treatment with NaOHaq leads to incorporation of sodium cations. Both treatments lead also to changes in surface acidity, as measured by Fourier transform infrared (FT-IR) monitoring of pyridine adsorption.