In the work discussed in this paper, titanium dioxide (TiO2) nanoparticles with the anatase structure were synthesized by use of a reflux technique under different conditions. Titanium(IV) isopropoxide (TTIP), in ethanol–methanol solutions, was used as precursor. Prepared TiO2 powders were characterized by XRD, SEM, and TEM analysis. Different conditions, for example reactant concentration (TTIP:MeOH:EtOH:H2O), reflux time and temperature, and calcination temperature, were changed to achieve to best nanocrystallite material. It was found that variation of all these conditions could strongly affect crystallinity, morphology, and crystallite size. The size and crystallization of nanocrystallites, and their uniformity, were controlled by changing these conditions. The crystallite sizes of nanoparticles, estimated by use of the Scherrer formula, were from 9 to 27 nm. TiO2 nanoparticles of minimum size were obtained by use of minimum reflux and calcination temperatures.