A new, simple and sensitive spectrofluorimetric method has been developed for the determination of aliskiren (ALS) in dosage forms and human urine. The method is based on the reaction between ALS and fluorescamine in borate buffer solution, pH 9, to give a highly fluorescent derivative which is measured at 482 nm after excitation at 382 nm. The factors affecting the reaction were carefully studied. The fluorescence intensity concentration plots were rectilinear over the range 140-1400 ng/mL with a limit of detection 13.47 ng/mL and limit of quantitation 40.81 ng/mL. The developed method was successfully applied to the analysis of the drug in tablets and human urine; the average recoveries (n=6) were 99.88 +/- 0.38% and 99.57 +/- 0.44%, respectively. The analytical performance of the method was fully validated and the results were satisfactory. The stability of the drug was studied by subjecting it to acidic, basic, oxidative and thermal degradation. Copyright (C) 2012 John Wiley & Sons, Ltd.