Abstract The thin‐layer chromatographic procedure for detecting and quantifying aflatoxin in peanuts is too time‐consuming, costly, and difficult to be practical for use by untrained personnel. A method based on millicolumn chromatography was tested and found to be both rapid and simple. Columns are prepared by filling a length of 4‐mm glass tubing with silica gel to a depth of about 4.5 cm. The millicolumn is developed in a chloro‐form‐methanol extract of a peanut sample. If aflatoxin is present, a blue fluorescent band at the lower end of the column is observed when the column is exposed to long‐wave ultraviolet radiation. Sensitivity is in the order of 5 ppb and an assay can be completed in 15–25 min. Some degree of quantification is possible by comparison with columns developed in extracts with known aflatoxin contents.