Further contamination can occur by the fungus during the unhyiegenic preparation and marketing of the butter, which explains the literature reports of higher Samples of roasted and unroasted peanuts, used for the preparation of peanut butter, were collected from the local markets in Omdurman Khartoum and Khartoum North to test for fungal contamination and aflatoxin formation. _Culturing peanuts on Potato Dextrose Agar (PDA), revealed Aspergillus flavus growth. _A representative sample (C) of unroasted peanuts was prepared and examined for aflatoxins using the flourometer (viacom series 4) method, which revealed 13.5 µg/Kg aflatoxin. _Roasted samples (A) revealed less aflatoxin1.5 µg/Kg, while in sample (B) no aflatoxin was detected. _The findings indicate serious health risks of consuming contaminated peanut butter, since it is widely reported that aflatoxins cause liver cancer. _concentrations of aflatoxin in butter which explains the literature reports of higher concentrations of aflatoxin in butter.