In this manuscript we investigate an inorganic, anionic promoter of barium sulfate crystallization. Sulfite ions are found to promote barium sulfate crystallization at low concentrations. Turbidimetric experiments show homogenous nucleation promotion and AFM results show possible 2D nucleation promotion in the presence of sulfite ions. Growth promotion appears to be mainly in the c-axis relative to the other faces according to morphology results at low S values. Analysis of the sulfite ion impact by assuming it completely oxidizes to sulfate did not adequately explain all experimental results, suggesting that these ions also interact in some other way. One mechanism by which sulfite might promote barium sulfate crystallization is by promoting de-solvation of the barium ion by weakly complexing with it.