Neodymium(III) hydroxide is an insoluble inorganic compound with the chemical formula Nd(OH)3.

[2][3] Neodymium(III) nitrate and ammonia water will react to produce neodymium(III) hydroxide:[4] If the amount of Nd(NO3)3 is 40g/L, the amount of ammonia water needed is 0.50 mol/L.

The ammonia water is mixed into the Nd(NO3)3 solution at the speed of 1.5mL/min, and polyethylene glycol is used to control pH.

The process will produce neodymium(III) hydroxide powder with grain size ≤1μm.

[5] Neodymium(III) hydroxide can react with acid and produce neodymium salts: For example, to create neodymium acetate with neodymium(III) hydroxide:[6]