A rapid and specific ion-pair reversed-phase high-performance liquid chromatographic method was developed for the determination of bleomycins. The use of 5-microns particles of less adsorptive reversed-phase packings and sodium perchlorate as ion-pairing reagent permitted a short analysis time and the transferability of the separations on different batches of the reversed-phase materials. The detection sensitivity and precision of the method demonstrated that the system is suitable for routine analysis.