A high-performance liquid chromatographic technique is described for the determination of milacemide and its primary metabolite glycinamide in rat plasma and cerebrospinal fluid. Milacemide and glycinamide are derivatized with fluorescamine to form a chromophore and a fluorophore and subsequent analysis using ultraviolet and fluorescence detectors, respectively. The extraction procedures are simple with a limit of detection 2 and 0.5 micrograms/ml for milacemide in plasma and cerebrospinal fluid, respectively, and 0.5 micrograms/ml for glycinamide in plasma or cerebrospinal fluid. The within-batch coefficients of variation for both analytes were less than 3%. Since only a small amount of sample is required, these techniques are well suited for the study of milacemide pharmacokinetics in the rat.