Capillary electrophoresis (CE) and it's applications in forensic toxicology are demonstrated by the investigation of amphetamine derivatives in "Ecstasy" tablets. The method is based on capillary zone electrophoresis (CZE) with a phosphate running buffer (pH 2.2). The drugs were dissolved in 0.01 N hydrochloric acid, diluted with distilled water and phenylephrine was added to the samples as an internal standard. A separation of the charged substances is obtained by the different velocities in the electric field. The qualitative determination can be made by the migration times or more accurately by the relative migration times. Other possibilities for identification are the UV-spectra using a diode array detector or the on-column standard addition procedure. By this procedure the sample solution is initially injected followed by the standard solution. Both are concentrated in the column before separation begins. CE shows clear advantages in comparison to high-performance liquid (HPLC) or gas chromatography (GC). The quantitative analysis was carried out using the internal standard phenylephrine. The values obtained for 56 "Ecstasy" tablets and powder containing amphetamine or its derivatives were compared in this study after analysis with CE and HPLC. The results were in very good agreement. Because of it's speed, the high resolving power and the possibility of identification with the on-column standard addition, CE is a powerful alternative to HPLC or GC for the investigation of "Ecstasy" tablets.