Abstract I n this study of the luminescence characteristics of griseofulvin we report corrected ambient temperature fluorescence excitation and emission spectra. The uncorrected fluorescence excitation and emission spectra on thin layer chromatographic plates are also reported. The quantum efficiency of fluorescence is calculated to be 0.108 and the mean phosphorescence lifetime determined to be 0.11 sec. The fluorescence lifetime is calculated to be 0.663 nsec. It appears t h a t phosphorescence emission may be the most sensitive spectral parameter; measurable phosphorescence can be obtained from solutions as dilute as 10-8M. No photodecomposition is apparent under reasonable conditions of light exposure.