Tarhana is a popular traditional Turkish cereal-based fermented food product mainly produced at home or at home-scale level. Some certain mould species can grow even at low moisture and pH values and produce aflatoxins in food. This study was conducted to determine aflatoksin levels in tarhana. For this purpose, a total of 138 tarhana powder samples were collected from bazaars in Istanbul and analyzed for aflatoxins, mould contamination, and some physico-chemical parameters. As a result, 32 out of 138 tarhana samples (23.2%) were found to be contaminated with aflatoxins in the range of 0.7-16.8 μg/kg, whereas 29 samples contained Aflatoxin B1 (AFB1) ranging from 0.2-13.2 μg/kg. All samples (100%) contaminated with moulds in the range of 1.4 × 10(1) -5.8 × 10(7)cfu/g. The average pH, moisture and a(w) results were detected as 3.82, 12.71%, and 0.695, respectively.