A new sensitive spectrophotometric method is developed for the determination of nitrite with imipramine hydrochloride coupled with 3-methyl-2-benzothiazolinone hydrazone hydrochloride in acid medium. Beer's law obeyed in the range of nitrite concentration of 0.02-7 mu g/mL and the molar absorptivity at 640 nm is 0.49 x 1041 mole(-1) cm(-1). Results obtained by using the proposed method for water samples agree well with those obtained by saltzman standard method.