A colorless solid, its conjugate base is a chelating agent, which is used for the quantitative determination of metal ions.

[4] In its photo-induced excited-state, 8-hydroxyquinoline converts to zwitterionic isomers, in which the hydrogen atom is transferred from oxygen to nitrogen.

They identified that the hydroxy group is on the benzene ring (but not its particular place) and called the compound oxyquinoline and α-quinophenol.

[7] Otto Fischer [de] and his student Karl Bedall made the compound from a sulphonic acid independently at about the same time, but misidentified its structure.

[11] The complexes as well as the heterocycle itself exhibit antiseptic, disinfectant, and pesticide properties,[12][13] functioning as a transcription inhibitor.