A spectrophotometric method has been developed for the determination of seven 1,4-benzodiazepines, namely: chlordiazepoxide, diazepam, nitrazepam, oxazepam, lorazepam, temazepam and cinolazepam. The method involves reduction of the target compounds using Zn/HCl and measuring the difference in the absorbance before and after reduction. The quantities of zinc and acid required for efficient reduction were carefully studied. 1–20 g ml^–1 of the compounds could be determined with < 1%="" error.="" the="" method="" was="" applied="" successfully="" to="" the="" determination="" of="" these="" compounds="" in="" pharmaceutical="" dosage="" forms.="" the="" results="" were="" sufficiently="" accurate="" and="" precise="" and="" comparable="" to="" those="" from="" the="" official="">