Aflatoxin М1 was in the spotlight of public attention in Serbia and in the region in 2013 due to high level of this mycotoxin found in milk and milk products. Maximum allowed concentration of aflatoxin M1 in milk by EU regulation is 50 ng/kg, while in the Republic of Serbia, allowed concentration by the current regulation is 250 ng/kg. During seven months period, from May to November, samples of raw milk were being taken from six farms, with 60 to 330 cows, from the region of Autonomous Province of Vojvodina, the Republic of Serbia, for the purpose of monitoring the occurrence of aflatoxin M1 in milk and its variation during this period. The highest level of 39.8 ng/kg was found in November, while the mean value for the whole period was 7.9 ng/kg. None of the samples had higher level of this mycotoxin than allowed by EU regulation or by current legislation of the Republic of Serbia. The second group of samples included a total of 38 samples of raw milk, from the period of October and November, were taken from different producers from the region of Vojvodina and analyzed on the occurrence of aflatoxin M1. In this group of samples, the occurrence of aflatoxin M1 was much higher, with the average value of 230 ng/kg. The highest found value was 864 ng/kg. In 13 samples, the aflatoxin M1 content was higher than the allowed by the legislation of the Republic of Serbia, while in 24 (63.2 %) samples determined concentration exceeded the value allowed by EU regulation. Data from this work suggest huge differences in the occurrence of aflatoxin M1 in milk between the producers in this region. Regular monitoring is necessary to avoid situation with the elevated level of aflatoxin M1 in milk. This measure will protect both the consumers and the producers of milk and milk product.