Promethium(III) nitrate is an inorganic compound, a salt of promethium and nitric acid with the chemical formula Pm(NO<sub>3</sub>)<sub>3</sub>. The compound is radioactive, soluble in water and forms crystalline hydrates.
Reaction of promethium and nitric acid:
Promethium(III) nitrate hydrate forms a purple-pink solid.
It forms crystalline hydrates of the composition .
Promethium(III) nitrate thermally decomposes to form promethium(III) oxide.