Brucellosis not only a zoonotic disease , but also causes heavyeconomic losses in animal industry, that give the high importance ofits control which depend mainly on accurate serological diagnosis andvaccination.Due to the importance of breast milk for children we aimed to studythe incidence of aflatoxins in human breast milk in some localitiesin Kalubia Governorate, beside exploration of the hepatotoxic effectsof aflatoxins. To achive this aim, 200 samples were collected from 22different localities in Kalubia Governorate duringMay,August,September and October,1991, from which 22 samples werefound contaminated wilh six different types of aflatoxins which areAFBl,AF81+Gl,AFMl,AFM2,AFGl and AFG2 distributed in nine districtswhere the highest number present in Moshtohor (11 samples) with overall percentage of 11%. The highest concentration presont was 200pg/ml of AFMl followed by AFBI-IG1,153 pg/ml, while the more prevalenttype was AFBl (40.90%).Also,we observed a relationship between the’ presence of aflatoxinsin breast milk and duration of lactation where aflatoxin percentagewas found to increase i~ the first four months of lactation and inthe 12th-16th months. Also,there are a seasonal variation ofnflatoxins in human breast milk where tho percentage of POSJtivRsamples were increased in dry season than in wet season.