Aflatoxins are a category of poisonous compounds found in most plants, milk and dairy products. The present research was carried out to detect the presence of aflatoxin M (AFM) in samples of milk collected from Hamadan province, Iran.Twenty five samples of ultra-high temperature (UHT) and 63 samples of pasteurized milk were collected and the amount of AFM was measured by an Enzyme-Linked Immunosorbent Assay method. In addition, the estimated daily intake (EDI) and hazard index (HI) of AFM was determined by the following equations:(EDI= mean concentration of AFM × daily consumption of milk/body weight; HI= EDI/Tolerance Daily Intake).AFM was detected in 21 (84%) UHT milk samples and in 55 (87.30%) pasteurized milk samples. Seven (28%) samples of UHT and 21 (33.33%) pasteurized milk samples had higher AFM content than the limit allowed in the European Union and Iranian National Standard Limits (0.05 μg/kg). None of the samples exceeded the US Food and Drug Administration limit (0.5 μg/kg) for AFM. EDI and HI for AM through milk were 0.107 ng/kg body weight/day, and 0.535, respectively.A significant percentage of milk produced by different factories in Iran (84% of UHT and 87.3% of pasteurized milk) was contaminated with AFM. Therefore, more control and monitoring of livestock feeding in dairy companies may help reduce milk contamination with AFM. As the HI value was lower than 1, it can be assumed that there was no risk of developing liver cancer due to milk consumption.