The purpose of this study is to investigate mycotoxin (Aflatoxin B1) in high school student blood samples. Thus, 350 blood samples were collected randomly from students in various schools in Al-diwanyia city, and then toxin was detected using ELIZA method. The results showed 287 ( 82% ) of student were had aflatoxin in their blood in a different concentration varying from 2.301 to 3.245 ng/ml and these concentrations were high (2.610  to  3.245) n/L in male rather than female  (2.301 to 2.541) ng/L. Intrahepatic AFTs-B1 is activated by the enzymes p450 hemogenic protein, which is reborn into AFTs-B1-8, 9 epoxide, which is responsible for the effects of cancer within the secreted organ. Based on the fact that AFB1 recorded the most important effects of strong malignant tumor disease in both humans and animals, and thanks to the acute problems related to the contamination of AF More attention has been paid to food and feed and its negative impact on public and economic health compared to various fungal toxins. Because absolute safety is incredibly difficult to achieve, many developing countries have tried to reduce aflatoxin toxicity under the rules that management exposure prohibits the limits of such toxins in food and feed. This research was therefore designed to determine the levels of aflatoxin B1 in secondary school students ' blood samples.