Kefir is fermented milk onlymade fromkefir grains and kefir cultures and nowadays consumedwidely around theworld. Itmay become contaminated with aflatoxin M1 (AFM1) which even in small quantities, have hazardous effects for human beings. Therefore, a practical and effective method is needed to be developed for the detoxification ofAFM1 contaminated milk or decreased its toxicity. It has been reported that specific lactic acid bacteria are able to remove or degradeAFM1 fromliquidmedia by physical binding. The objective of this study was to detect the effect of kefir starter and Lactobacillus acidophilus to bind AFM1 in kefir made from milk spiked with 500 pgAFM1mL-1.Accordingly, five levels of kefir starter (2Â 4Â 6%Â 8 and 10%) as group 1 and five levels of Lb. acidophilus (0.1Â 0.3Â 0.5Â 0.7 and 0.9%) with constant amount of kefir starter (4%) as group 2 were used. After 48h, theAFM1content of kefir sampleswasmeasured by competitive ELISA technique. Statistical analysesÂ in group 1Â showed that the sample containing 6% kefir starter had the most reduction inAFM1 concentration (88.17%) whichwas significant (p<0.05). In group 2 the sample containing 0.9% Lb. acidophilus and 4% kefir starter had the maximum amount of AFM1binding (89.04%) and there were no significant differences (p<0.05) between 0.3Â 0.5 and 0.7% levels in AFM1 reduction. GenerallyÂ the effect of kefir starter (alone)wasmore than Lb. acidophilus inAFM1 binding and the combination of these strains had synergistic effect inAFM1 reduction. These findings affirmed that particular bacteria and yeast used in this study can offer decontaminating AFM1 kefir.