By the use of an enzyme multiplied immunoassay technique (EMIT), a convenient and fairly sensitive semiquantitative screening method was established for methamphetamine (MA) incorporated in hair. MA in a 10-mg portion of hair was extracted into 5M HCl/methanol (1:20, v/v), and the extract reconstituted in 100 microL water was assayed with double-concentrated EMIT d.a.u. Amphetamine Class assay reagents. The optimal cutoff concentration of MA in hair was found by receiver operating characteristic analysis to be 1.0 ng/mg, and the detection limit was calculated to be 0.5 ng/mg. The semiquantitative screening was possible over the concentration range from 1.0 to 200 ng/mg, and the results are in good agreement with those by gas chromatographic-mass spectrometric (GC-MS) determination. Although all positive results must be confirmed by either GC-MS or a specific alternative methodology, this method not only provided reliable screening suitable for drug enforcement purposes, but it also allowed sectional profile analysis of MA in hair while requiring only a 10-mg hair specimen.