A rapid extraction procedure for fingerprint chromatogram of different types of Mentha piperita L. (Labiatae family) is presented. The extracts were analysed by gas chromatography and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds identified by the gas chromatography-mass spectrometric analysis of M. piperita L, were menthol, menthone, isomenthone, 1,8-cineole, menthyl acetate, limonene, beta-myrcene, carvone. M. piperita L, oil had the active principles: menthol, menthone, isomenthone, menthyl acetate, alpha-pinene, beta-pinene, champhor, limonene, linalool, piperitone. M. crispa L. showed carvone as major component. (C) 2000 Elsevier Science B.V. All rights reserved.