The simultaneous determination of zinc and cadmium using derivative synchronous and multiwavelength synchronous spectrofluorimetry is described. Effects of experimental variables on the fluorescence intensities and on the spectral resolution of the fluorescent chelates of these metals with 8-(p-toluenesulfonamido)-quinoline (TSQ) in a sodium lauryl sulfate micellar medium have been studied. Mixtures containing 10-200 μg L(-1) Zn and 15-250 μg L(-1) Cd have been analyzed with good results. The proposed method has been applied to a biological sample.