The pressure dependence of the photodissociation quantum yield of acetone has been determined in different buffer gases at 308 nm. Results by Stern-Volmer analyses are in accordance with a suggested photolysis mechanism. Luminescence spectra, lifetimes and transition dipole moments have been determined. The energy transfer process by O-2 to give O-2((1)Delta(g)) is of minor importance in the case of the singlet excited state of acetone, while it is the dominant deactivation process for the triplet state.