The gas-liquid chromatographic behavior of a group of zearalenones has been investigated through the use of both selective and nonselective stationary phases. Separation of these compounds can be effected using conditions similar to those employed for steroid work, differentiation being accomplished on the basis of molecular weight, unsaturation, functional groups, and stereochemistry. Functional group alteration has been employed to improve separations and the quantitative aspects of analysis. Separation of a pair of epimeric alcohols proved to be especially difficult, requiring the use of several approaches. The contribution of the phenolic group at the 2 position to retention behavior is considerably smaller than that of the 4-phenol, a difference ascribed to the ability of the former to intramolecularly hydrogen bond to the carbonyl group of the lactone. These methods have been employed to identify the major urinary metabolite of one of the compounds of this series in the sheep.