Other hydrates are also reported in literature, such as the trihydrate.

[1][2][3] Indium(III) nitrate hydrate is produced by the dissolution of indium metal in concentrated nitric acid followed by evaporation of the solution:[1][2][3] The hydrate first decomposes to a basic salt and then to indium(III) oxide at 240 °C.

Anhydrous indium(III) nitrate is claimed to be produced by the reaction of anhydrous indium(III) chloride and dinitrogen pentoxide.

It also reacts with sodium tungstate to form In(OH)WO4, [In(OH)2]2WO4, NaInWO4 or In2(WO4)3 depending on pH.

The pentahydrate consists of octahedral [In(NO3)(H2O)5]2+ centers as well as two nitrates and is monoclinic.