A rapid immunochromatographic assay was developed and validated for detection of 1-aminohydantoin (AHD) in urine specimens. Colloidal gold-labeled polyclonal antibody specific to AHD derivative was used as the marker; based on the competitive reactivity theory, the metabolite of nitrofurantoin after derivatization with benzaldehyde would compete with carboxyphenyl AHD derivative-conjugated ovalbumin. The test strip could efficaciously detect the novel analyte with a visual detection limit of 10 ng mL−1 and high specificity. The reliability of the assay was determined by testing 80 standard samples comparing with enzyme-linked immunosorbent assay. The semi-quantitative detection was accomplished in less than 15 min with low cost, especially for requirements of rapid and simple screening. This is the first publication of an immunochromatographic assay for detection of nitrofuran residues. Copyright © 2008 John Wiley & Sons, Ltd.