The electronic properties of tris(8-hydroxyquinolinato)aluminium(III) (AlQ(3)) have been revisited using the screened hybrid Heyd-Scuseria-Ernzerhof density functional theory. We show that such approach very well accounts for the experimental occupied (valence band spectrum) and unoccupied (inverse photoemission spectrum) states. Furthermore, the density of states projected onto nitrogen, oxygen, and carbon are compared with soft x-ray adsorption and emission spectroscopy, showing a very good agreement between theory and experiments. Finally, a fully theoretical interpretation of the carbon 1s core level is proposed.