Abstract A simple method has been introduced by means of which fluorescence spectra can be obtained directly from a thin-layer chromatogram. The usefulness and sensitivity of the method have been demonstrated for a wide variety of polycyclic compounds. Some of the spectral differences between the dry and wet spots have been found to be useful analytically. The ease of applicability of the method has been proved through the characterization of the spots obtained from the thin-layer chromatogram of a coal-tar-pitch basic fraction. Benzo(h)quinoline, methylbenzo(h)-quinoline, dimethyl(or ethyl)benzo(h)quinoline, benz(c)acridine, and methylbenz(c) acridine have been identified in the sample.