AbstractA rapid screening method for detecting aflatoxins in cottonseed has been developed. Using long‐wave ultraviolet light and samples containing aflatoxins, the fibers on a few cottonseed fluoresced a greenish yellow and the ends of some sticks and stems (foreign material) fluoresced with a bluish color. Nine out of 10 of the 2300 samples of cottonseed were correctly screened during the last two years of the study. In only one category, 1–10 ppb aflatoxins, was there an appreciable error in the screening method.