Wheat flour is a commodity with a high risk of aflatoxins (AFs) contamination. During the bread making there are many processes that can affect the AFs stability. The effect of bread making process using different yeast types on AFs levels was investigated. For this purpose, standards of AFs including B and Gwere added to flour and then bread loaves were prepared. Three types of commercially available yeast including active dry yeast, instant dry yeast and compressed yeast were used for dough preparation. AFs levels in flour, dough, and bread were analyzed by high performance liquid chromatography (HPLC) with fluorescence detector. The results showed that maximum reduction in aflatoxin levels observed during first proof while the least decline was seen for the baking stage. The order of AFs reduction in bread making process was AFB₁>AFB₂>AFG₁. Furthermore, the results indicated that the most effective yeast for AFs reduction was instant dry yeast.