The effect of a selected number of parameters of the Low-Temperature Aqueous Synthesis (LTAS) on BaTiO 3 particle size was investigated by the statistical design of experiment approach. Different syntheses were carried out changing the value of six physico-chemical parameters involved in the process, following the scheme of a 2 6-2 fractional factorial design. The characterisation of the submicron powders produced shows variations of the average size in the range 30–55 nm, deduced from specific surface area measurements. The statistical analysis of experimental results, performed by the ANOVA method, allows to ascribe such variations to the effect of solutions concentration, stirring energy and precursors mixing conditions. The significance of such parameters, together with the apparent ineffectiveness of the ageing time, is discussed. Also the XRD measurement of barium carbonate amount is presented and its dependence on experimental conditions is discussed.