Sixty-seven pig feed samples were examined for the presence of aflatoxins by the method after Velasco, with simultaneous qualitative determination by the thin-layer chromatographic method. All samples were collected at about the same time (June 1977) from central stores, feed preparing plants, storage containers and feeding lines on farms. On the whole, the feeds formed a representative sample of the conditions of pig feed storage and treatment. The presence of aflatoxins was proved in 18 samples (26.8%). One sample (1.4%) showed just traces of aflatoxin, six samples (8.4%) contained 0.014 to 0.45 mg aflatoxins, eight samples (11.2%) contained 0.10 to 0.30 mg aflatoxins, and three samples (4.2%) had 2.7 to 3.5 mg aflatoxins per 1 kg of feed. The samples with the highest aflatoxin concentrations came from metallic storage containers for complete feed mixtures in front of the pigsties.