Present paper reports the effect of change of spandex denier on the properties of stretchable lyocell-spandex cover spun yarn. The core component was spandex with 20D and 40D while sheath consisted of lyocell yarn; eco-friendly regenerated cellulosic yarns. The stretchable cover spun yarns were produced in a hollow spindle spinning frame. ANOVA was applied to study the significant effect of presence of spandex as well as effect of variation in denier of spandex was also noted. It was observed that yarn count, tenacity, breaking strength, elongation and imperfection of yarn was influenced due to presence of spandex. However, change in the denier of spandex affected all parameters except tenacity and unevenness.