A high-pressure liquid chromatographic procedure for quantitative dexamethasone and dexamethasone sodium phosphate determinations in all types of commercially available pharmaceutical dosage forms was developed. The method also separates dexamethasone from its phosphate salt and separates dexamethasone or its salt from a number of inactive ingredients such as benzoic acid, benzyl alcohol, some colors, creatinine, and parabens. Inactive ingredient concentrations may be estimated without additional cost. Part of the parabens present in the commercial injections may be adsorbed by the rubber closures.