Capillary electrophoresis was utilized for the rapid determination of psilocybin in the hallucinogenic mushroom Psilocybe semilanceata. Following a simple two step extraction with 3.0 + 2.0 ml methanol, the hallucinogenic compound was effectively separated from matrix components utilizing capillary zone electrophoresis (CZE) with a 10 mM borate/phosphate running buffer adjusted to pH 11.5. Quantitation was accomplished utilizing barbital as internal standard. The calibration curve for psilocybin was linear within 0.01 - 1 mg/ml, while intra-day and inter-day variations of quantitative data were 0.and 2.5 % RSD respectively. For identity confirmation, rapid derivatization with propyl chloroformate in the methanolic extract and re-analysis was performed in order to effectively support the identification of psilocybin. In addition to this alkaloid, the method was capable also for the determination of the structurally related compounds baecystin and psilocin.