A spectrofluorometric method was developed, based on the formation of fluorescent derivative with NBD-Cl and nortriptyline in aqueous medium. The optimum reaction conditions were established as follows: the pH was found to be 8.0 and NBD-Cl/amin mole ratio was 15. The reaction completed at 70oC within 30 min. after completion of the reaction, the reaction product was acidified with 0.1N HCl and diluted with dioxane. The fluorescence intensity was measured at 530 nm using 436 nm excitation filter. A linear relationship existed between relative fluorescence intensity and concentration over the 10-50, 50-250 and 250-1250 ng.ml-1 concentration ranges of amine. The proposed method was applied to determination of this substance in tablets. The results were compared with those obtained by the British Pharmacopoeia (BP) method at 95% confidence level in respect of t- and F- tests of significance. Keywords :