[8] The main commercial value of RuO4 is as an intermediate in the production of ruthenium compounds and metal from ores.

Ruthenium is separated from OsO4 by reducing RuO4 with hydrochloric acid, a process that exploits the highly positive reduction potential for the [RuO4]0/- couple.

RuO4 readily cleaves double bonds to yield carbonyl products, in a manner similar to ozonolysis.

OsO4, a more familiar oxidant that is structurally similar to RuO4, does not cleave double bonds, instead producing vicinal diol products.

[12] Because RuO4 degrades the "double bonds" of arenes (especially electron-rich ones) by dihydroxylation and cleavage of the C-C bond in a way few other reagents can, it is useful as a "deprotection" reagent for carboxylic acids that are masked as aryl groups (typically phenyl or p-methoxyphenyl).

Although used as a direct oxidant, due to the relatively high cost of RuO4 it is also used catalytically with a cooxidant.

It is used to expose latent fingerprints by turning to the brown/black ruthenium dioxide when in contact with fatty oils or fats contained in sebaceous contaminants of the print.