Nanocrystalline Ni0.85Se and NiSe2 were prepared through the reaction between NiCl(2)(.)6H(2)O and elemental selenium at 50 degreesC, using (N2H4H2O)-H-. as reductant and pyridine as solvent. TEM images showed that the Ni0.85Se and NiSe2 particles were both spherical in shape with sizes of about 20 nm. Solvent pyridine plays an important role in the formation of nanocrystalline nickel selenides due to its appropriate N-chelation ability and alkalescence.