Feedstuffs and mixed feeds used for poultry and pig nutrition in Colombia were analyzed for aflatoxins by using a liquid chromatographic technique with a limit of detection of 1 microgram/kg for each aflatoxin (B1, B2, G1, and G2). Samples of grain sorghum, maize, processed soybean, rice meal, cottonseed meal, and poultry and pig feeds, representative of Colombian production for the 1995-1996 harvest, were taken from feed-manufacturing plants in various cities. Aflatoxins were detected in 11 of 45 samples of sorghum, 4 of 33 samples of maize, 8 of 22 samples of rice meal, 15 of 17 samples of cottonseed meal, 1 of 12 samples of other feedstuffs, 12 of 30 samples of poultry feed, and 7 of 16 samples of pig feed. Aflatoxins were not detected in soybean. Only 9 of 58 positive samples contained total aflatoxin levels exceeding maximum tolerable limits in Colombia.