The single crystals of CdxNiyCrzSe4 (x+y+zapproximate to3) were prepared by a chemical vapour transport in closed silica tubes using CdSe and NiSe with CrCl3 as the transport agent. The chemical compositions of selected crystals have been determined by X-ray electron probe microanalyzer. The influence of the Ni substitution into the spinel structure of CdCr2Se4 has been analyzed on the basis of the experimental data for the magnetization in the external magnetic fields. The nickel substitution did not cause an observable change in the saturation magnetic moments in the measured samples. (C) 2004 Elsevier B.V. All rights reserved.