The main effect of khat assumption is a psychoactive stimulation similar to that produced by amphetamines. The substances responsible for the central nervous system stimulatory effect are alkaloids with an amphetamine-like structure: cathinone, cathine and phenylpropanolamine (PPA) [1,2]. In the last years, the Tribunals of Busto Arsizio and Bergamo gave us the task to analyze all the materials suspected to contain khat active principles. Thus, due to the high number of samples, we developed a fast, effective and reliable analytical procedure able to simultaneously detect cathinone, cathine and PPA by means of capillary electrophoresis, a technique which has been recently introduced among the methods officially accepted by the federal court of the United States, because of its fastness, versatility, sensibility and economy [3]. The active principles were resolved in 8 min with a 25 mM pH 2.5 tris-phosphate buffer, the capillary being operated at 30 kV. In these conditions we were able to separate in an efficient way cathine from PPA which often coelute in other analytical procedures. LOD, LOQ and intra-day/inter-day repeatability were determined. In order to optimize the quantitative determination of the most active alkaloid, several parameters of the analytical procedure, such as extraction conditions and conservation of the vegetable material, were evaluated. Moreover the electrophoretic performances of several molecules were studied with the aim of identifying an internal standard, which could help in the quantification of cathinone, cathine and PPA. Nicotinamide revealed as a suitable IS for the quantification of the active principles of Catha Edulis. The good results obtained show that CE can be successfully applied for the forensic analysis of the vegetable material belonging to this species.