In this study, 150 UHT milk samples were analyzed for aflatoxin M1. They were obtained from supermarkets in Erzurum city. The occurrence and concentration range of AFM1 in the samples were investigated by ELISA method. Fifty-nine percent of the UHT milk samples contained AFM1. AFM1 levels in 16 (10.7%) UHT milk samples exceeded the maximum tolerable limit of the European Community and the Turkish Food Codex. It was concluded that high AFM1 level is an important problem threatening the public health in Turkey.