AbstractA simple and improved gas chromatographic method has been developed for the quantitative analysis of nalidixic acid. The method is based on the derivatization of nalidixic acid with pentafluorobenzyl bromide in acetone, using potassium carbonate as a base‐catalyst. The derivative obtained was chromatographed on an OV‐101 column and the pentafluorobenzyl ester of cinoxacin was used as an internal standard. The method was satisfactorily applied to the analysis of nalidixic acid in tablets, and the results agree well with those obtained using the UV absorption spectrophotometric met