The thermal behaviour of intimate mixtures of different mole ratios of potassium bromate and chromium(III) oxide has been studied using TG and DTA techniques in static air atmosphere. The products have been characterised by chemical analysis, infrared spectroscopy and X-ray diffraction studies. The studies indicate that Cr2O3 lowers the decomposition temperature of potassium bromate and is oxidised to Cr(VI). Each mole of Cr(III) takes up two moles of KBrO3, to give potassium dichromate, and four moles of KBrO3, to form potassium chromate. © 1994.