A collaborative study was made of qualitative tests for added antioxidants in oils and fats. Samples of corn oil, edible tallow, and lard to which 5, 5, 10, and 15 ppm of propyl gallate, butylated hydroxyanisole, butylated hydroxytoluene, and nor-dihydroguaiaretic acid, respectively, had been added, plus blank samples of the oil and the fats were analyzed by 9 collaborators. The tests employed were previously described in This Journal, 45, 244 (1962). The present report includes an extraction procedure for separation of individual antioxidants, after which the qualitative test are applied. All collaborators identified the added antioxidants correctly. (Four of the nine repeated the analyses of the samples, which were resubmitted to them in different sequence and with different identifications.) The procedure is considered suitable for routine screening, since oils and fats in commercial use contain a considerably higher level of antioxidants than were added to these collaborative samples.