Abstract The emission spectrum of fluoranthene, one of the polycyclic aromatic hydrocarbons on the Priority Pollutant list of the Environmental Protection Agency, has been the subject of a long-standing controversy. While some authors reported two emission band contours for this compound, starting at about 350 and 410 nm, respectively, others observed only the 410 nm band. In this study the controversy is put to an end. A sample of commercially available fluoranthene is investigated with high resolution Shpolskii spectroscopy, reversed-phase liquid chromatography and gas chromatography/mass spectrometry. It appears that the 350 nm emission is caused by an impurity in the fluoranthene sample. The impurity is a substituted phenanthrene, most probably acephenanthrene. The 410 nm emission is due to the fluoranthene S 1 S 0 fluorescence.