A procedure for the determination of fumagillin, an antibiotic of Aspergillus fumigatus in fish meat samples, using reversed-phase high-performance liquid chromatography is described. Liquid chromatography was performed on an octadecylsilane column using acetonitrile-water-phosphoric acid solution as mobile phase, with detection at 350 nm. Two different types of sample preparation were developed, clean-up and enrichment, and the limits of quantification were 100 ng/g and 5 ng/g, respectively, in fish meat. The recovery was 75 +/- 3% in the concentration range 100-500 ng/g. To introduce the methodology and demonstrate its usefulness, a practical experiment was performed. Trouts fed with fumagillin were examined for elimination of fumagillin. After 24 h, the concentration was shown to decrease to below 100 ng/g.