Simultaneous quantitation of several components in a sample is an alternative to the sequential determination. It avoids the separation on masking steps, simplifying the automatization of the analysis. The solvent extraction procedure is used for the determination of copper, cobalt and nickel simultaneously at microgram levels. The reagent diethyldithiocarbamic acid has been examined for the high performance liquid chromatographic separation of copper(II), cobalt(II) and nickel(II) chelates (range pH 9–11) on Reversed Phase High Performance Liquid Chromatography (RP–HPLC) columns (150 x 3,9 mm) packed with Nova Pak C18, 4 m. An aliquot of sample containing copper, cobalt and nickel in a mixture was transferred to a well-stoppered test tube to which was added reagent [diethyldithiocarbamic acid 0,5% in ethanol:water (1:1), pH 10] and 10 ml organic solvent (ethyl ether). After shaking with mechanical shaker for 5 min, the organic layer was separated and 20 l transferred to another tube containing methanol (1ml). The methanolic solution (15 1) was injected, on the reversed phase HPLC column. The complexes are eluted with a binary mixture of methanol and water (75:25) at a flow-rate of 0,5 ml min-1. The detection is carried out with a UV detector at 260 nm. The method shows several adventages: short analysis time, minimized sample preparation, minimized effect of interfering ions, a low detection limit (50 ppb for nickel, 30 ppb for copper, and 5 ppb for cobalt) and good reproducibility, making it suitable for many types of samples, including alloys.