Abstract: A method for producing stable copper(II) hydroxide. The method comprises the treatment of a copper metal powder in an acidic aqueous solution containing acetic acid in the pH range less than 3.0 and at temperature below 30 ° C. under stirring conditions. To this acidic solution an alkali metal hydroxide solution is added to raise the pH above 7.0 to form copper(II) hydroxide. The method also comprises preparation of copper(II) hydroxide by treating the copper salts water solution with an alkali metal hydroxide solution in the pH range 7.0 to 12. To improve the stability of the copper(II) hydroxide prepared according to all the said method, a small amount of alkali or alkaline metal gluconate can be added to the suspension before or after the reaction.