In the last years, all the vegetable material supposed to belong to the Catha Edulis species, seized at the Malpensa and Orio al Serio airports, were analyzed in our laboratory on behalf of the Tribunals of Busto Arsizio and Bergamo, respectively. After a preliminary botanic examination, the quali-quantitative determination of the active principles cathinone, cathine and phenylpropanolamine (PPA) was carried out by means of GC/MS and GC/FID techniques, which meet the requirements of the forensic analyses. We developed a fast, effective and reliable derivatization procedure which allowed to simultaneously detect cathine and PPA, whose discrimination is mandatory since PPA is not a psychoactive agent. Cathine was distributed in the various parts of the plant (leaves and stems) and its quantity ranged from 0.03% to 0.17% of the weight of the vegetable material; PPA was not detected in the twigs and its quantity in the leaves ranged from 0.07% to 0.16%. The quantitative determination of cathinone was carried out directly on the methanol solution after maceration of the vegetable material, its quantity ranging from 0.02% to 0.10%. No significant difference in the content of the two active principles was found between the fresh and the dried material.