Fourier transform–based spectroscopic imaging was used for direct, time-resolved, analysis of UV-irradiated anthracene crystallites. Well-resolved fluorescence spectra were obtained at a spatial resolution of 1 μm. The appearance of such photochemical by-products as dianthracene and anthraquinone was monitored throughout the irradiation experiments. Under deaerated conditions, photolysis of anthracene was accompanied by formation of dianthracene. When performed under aerated conditions, however, the spectral data indicated formation of both dianthracene and anthraquinone. Spectral features obtained for the directly monitored photolysis of anthracene are discussed in respect to the structural and compositional modifications in such crystallites. Capabilities of the spectral imaging device for the quantification of the photochemical products of anthracene are discussed.