In this study, it was aimed to investigate the morphologic effects of sodium benzoate (SB) and citric acid (CA) , additives used in food, on rat liver and liver tissues and changes in total sialic acid (TSA) levels. A total of 30 Wistar albino rats weighing 200-250 gr were divided to 3 groups with 10 in each. Rats in control group, SB group and CA group were administered on by gavage tap water, Na-benzoate (2442 mg/kg body weight) and citric acid (576 mg/kg body weight) once daily respectively for 10 days. At the end of the experiment, animals in control and experiment groups were opened and heart blood, hepatic and renal tissues were obtained. Removed tissues were examined under light and electron microscopy following routine follow up procedures. TSA amounts in serum and tissues were measured with spectrophotometric method. In SB and CA groups, disruption was observed in hepatic tissue engineering, vacuolization was observed in hepatocytes and also pyknotic nuclei, nucleus losses and hypertrophy were observed. In SB and CA groups, pyknotic nuclei were observed in renal tubular cells, membrane injury was observed in apical and basal surfaces of tubular cells, degeneration was observed in glomerular structures and irregularity was seen in tubular structures. Plasmarhexis, losses in mitochondrial crista, degeneration in outer membrane and nuclear membrane of mitochondria, vacuolization in hepatocytes and myelin figures were observed electromicroscopically due to SB and CA. In renal tissues, electronmicroscopic degenerative changes included electron-dense granules, crista losses in mitochondria, irregular microvilli, vacuolization and plasmarhexis in cytoplasma of tubular cells, irregularity in chromatin material, disruption in basal membrane, enlargement in ER sacs. In SB groups, serum TSA amount was seen to decrease significantly (p<0.05) and a significant difference was not seen in CA group. It was seen that sialic acid amounts significantly decreased both in liver and kidney tissues in SB group (p<0.0001); in CA group, while a significant difference was not seen in hepatic tissues, renal TSA level was detected to increase significantly (p<0.0001). When effects of SB and CA on TSA amount and morphologic degenerations in liver and renal kidney were evaluated together, we consider that more detailed studies are required about the use of these food preservatives