The present research focused on the effects of spandex and yarn count parameters on the properties of elastic core-spun vortex yarns. The experiment and test results indicated that the various properties of elastic core-spun vortex yarns were significantly affected by spandex and yarn count. Coarser yarns showed lower unevenness, imperfection and breaking elongation values than finer yarns. Core-spun vortex yarns containing spandex showed lower tenacity and higher breaking elongation values than vortex spun yarns. The liveliness of spandex affected the hairiness proper- ties of core spun vortex yarns. The number of fibers in the cross section and the liveliness of spandex must be evaluated together during the manufactur- ing process of elastic core-spun vortex yarns.