A derivative spectrophotometry was developed to determine miconazole in cream formulations that contain benzoic acid as preservative. The procedure was based on the linear relationship in the range 100-500 μg ml−1between the drug concentration and the second derivative amplitudes at 276 nm. Results of the recovery experiments performed on various amounts of benzoic acid and of the determination of miconazole in cream confirmed the applicability of the proposed method to complex formulations.