Three-component solvent systems, viz formic acidpropanol-2-acetone, formic acid-butanol-1-ethyl methyl ketone, formic acid-dimethylsulphoxide-ethyl methyl ketone and formic acid-propanol-2-1,4-dioxane have been used to separate nickel from cobalt as its chlorosulphate on silica gel layer. The mobility of nickel chlorosulphate is found to be greater in solvent systems with higher formic acid concentration and it increases with the increase in formic acid concentration in the mobile phase. The mobility of cobalt chlorosulphate also changes slightly with the change in concentration of formic acid in the mobile phases. Both the chlorosulphates are strongly adsorbed on silica gel layers in absence of formic acid.