A reversed-phase high-performance liquid chromatographic technique is described for the analysis of cyclophosphamide in the presence of its hydrolysis products. The drug was quantified using a UV detector at a low wavelength. A single band was observed for the intact drug, which was well separated from tis hydrolysis product(s). Quantificaiton was obtained with adequate precision by the use of an injector loop or a suitable internal standard (hydrocortisone). The technique requires no extraction of the drug from aqueous solution or derivatization for analysis. The method was applied to partially hydrolyzed and to known solutions of cyclophosphamide. With suitable modification, the method may be useful for analysis of dosage forms but probably lacks the sensitivity necessary for analysis of the drug in biological samples.