Abstract Mycotoxins are secondary metabolites produced by some filamentous fungi, which can cause toxic effects in humans and animals. The purpose of the study was to report the influence of postharvest conditions of grains and animal feed on the occurrence of mycotoxins in milk and dairy products which are widely consumed worldwide and have several health benefits for consumers. Among the most toxic mycotoxins are aflatoxins (AFs), with AFB1 being the most toxic and present in grains and cereals used in the feeding of dairy cows. After ingestion, AFB1 is converted to AFM1, which is excreted in milk, being a source of direct contamination to consumers of this product and dairy products. Thus, knowledge about this substance and the care that can be taken to reduce the consumption of contaminated food is a matter of great importance concerning public health and food safety. This review reports that the temperature and humidity at which the grains are stored, are the main conditions that can be controlled during storage, aiming to reduce the growth of fungi and the production of mycotoxins. This work reinforces that the continuous control of mycotoxins in milk and dairy products is of vital importance to obtain a safe product. Besides, strategies to mitigate the development of fungal contamination have been carefully revised to prevent the formation of these toxic substances.