Food additives are substances that become part of the food when added during the processing or production of the food. Potassium bromate (KBrOs) is one of the food additives which are often used in bakeries as flour improver and dough conditioner. It is nephro and neurotoxic in humans and carcinogenic in rodents. In addition, experiments aimed at elucidating the mode of carcinogenic action have revealed that KBrOQ3 is a complete carcinogen. The objective of this study was to investigate the toxic and carcinogenic effects of various levels of dietary potassium bromate in male and female rats. The criteria for assessment include its effects on growth and pathological, immunohistochemical, histochemical, and biochemical alterations. In this experiment a total of 105 albino rats of both sexes, weighing 120 g were used, they were kept under standard conditions and housed in metallic cages under standard conditions and had free access to water and a standard diet. The animals were left for a week, as an adaptation period. The rats used were 45 male, 45 female and 15 rats of both sexes used as control. Both male and female rats were divided into three groups. KBrO3 dissolved in water at concentrations of 200, 400, and 600 ppm respectively was administered to male and female group rats daily till the end of the experiment. After 6, 9, and 14 months ten animals from each group (5 male and 5 female) and five from the control were sacrificed by cervical dislocation. Histological examination of the liver revealed congestion of its blood vessels, various degenerative and necrotic alterations with toxic hepatitis, and bile duct hyperplasia. Carcinogenic and dysplastic alterations were recorded in some cases, especially after 9 and 14 months of potassium bromate treatment which gave positive results by using Proliferating cell nuclear antigen (PCNA) as an immunohistochemical stain. Liver function markers showed a significant increase in the level of Alanine Aminotransferase (ALT) and Aspartate aminotransferase (AST).