We report the UV photodissociation spectrum of mass-selected Cu(NO3)(3)(-) ions at photon energies between 3.0 and 5.6 eV. Upon photon absorption, Cu(NO3)(3)(-) undergoes reductive dissociation losing neutral NO3 and resulting in the formation of Cu(NO3)(2)(-). The experimental results are discussed and interpreted with the aid of quantum-chemical calculations. The parent ion is calculated to have C2 symmetry with a strongly distorted octahedral coordination around the Cu ion. Time-dependent density functional theory is used to describe the accessible electronic transitions, which can be characterized as ligand-to-metal charge transfer transitions from the nitrate ligands to the copper ion.