Maxiban and Monteban are 2 products marketed by Elanco Animal Health. They contain narasin and are used for the prevention of coccidiosis in chickens. Products used in the European market must be regularly re-registered with new data to support label claims. This study was undertaken as part of such a re-registration effort. A method for the determination of narasin in poultry tissue was previously registered with the authorities; however, a method with more environmentally friendly solvents was desired. The Canadian Food Inspection Agency accomplished this goal and published an improved method. In order to register the method with European authorities as the official Elanco method for determination of narasin, Elanco scientists were required to provide validation data for all edible poultry tissues. This paper shows the validation of the method to detect residues of narasin using solid-phase extraction followed by liquid chromatographic analysis utilizing post-column derivatization.