Background: Environmental factors including food toxicants are considered important in incidence of different malignances. Among these factors, hydroxymethylfurfural (HMF), as one of the heat damage indices, is attributed to induction of both mutagenic and carcinogenic effects. Little is known about the DIETARY EXPOSURE to this bioactive compound. The aim of present study was to determine HMF content, its bioaccessibility and to look for any correlation between HMF level and physicochemical parameters.Methods: In order to conduct this experimental study first, each type of traditional Iranian flat breads including Lavash, Taftoon, Barbari and Sangak were selected with simple sampling.The breads were analyzed for some physicochemical properties including moisture, ash, pH, protein, total carbohydrates and fiber. HMF content of the breads was measured by high-performance liquid chromatography in pre and post digested samples to calculate its bioaccessibility. The model consisted of a peptic digestion and a subsequent intestinal digestion. The bioaccessibility of HMF from breads was calculated by dividing HMF concentration in post-digested breads by HMF concentration in pre-digested breads.Results: The mean (SE) concentration of HMF between the four types of breads was significantly different before the in vitro digestion but not among the digested samples. HMF content of Taftoon, Sangak and Barbari decreased after digestion.A slight increase was observed for Lavash. The mean (SE) concentration of HMF were 48.5 (8.09) and 40.4 (6.89) mg/kg of the test items in pre and post digestive samples respectively, implying 83.0% bioaccessibility. Correlation analyses between physicochemical properties of the breads and HMF content before digestive process revealed a moderate reverse relationship between HMF level and carbohydrate content of breads (r=-0.5, p=0.003).Conclusion: It is concluded that both HMF content and its bioaccessibility from traditional Iranian breads were high.Resultant value is above of the threshold of concern (1600μg HMF/day). As traditional bread is one of the main DIETARY items in Iranian food basket, it seems necessary to apply a strategy for modifying the baking method of bread and its consumption to decrease HMF content and its bioaccessibility.