A method is described for the determination of the factors in tylosin base and tylosin tartrate as raw materials and in dosage forms. The reversed-phase chromatographic system is compared with other similar systems in terms of selectivity towards the major tylosin factors and an aldol condensation degradation product observed in tylosin injection. Experimental conditions affecting the separation of the components are discussed, together with procedures to demonstrate system validity. It is considered that the methods developed provide appropriate procedures for inclusion in pharmacopoeial monographs for tylosin, tylosin tartrate, tylosin premix, tylosin soluble powder, tylosin tablets and tylosin injection.