A new lanthanide-sensitized luminescence system: europium-sparfloxacin-1,10-phenanthroline-sodium dodecyl sulfate has been discovered. The spectrofluorimetric properties of the system were studied. The effect of experimental conditions on the fluorescence intensity was defined. Under the optimum conditions, the fluorescence intensity of the system is a linear function of the concentration of europium in the range 5.0 x 10(-9) - 1.0 x 10(-6) mol L(-1) and the detection limit is 1.0 x 10(-10) mol L(-1). The system was used for the determination of trace amounts of europium in rare earth samples with satisfactory results.