Urethral trauma caused by urethral dilation often leads to complications including gross hemorrhage and inflammation. The injury of the urethral mucosa is, in a large part, due to the shearing forces imposed on it during the introduction of dilation devices. In this article, a radially expanding sheath for urethral dilation is hypothesized by the authors. This device aims to reduce the axial forces during the insertion of dilators, thereby protecting the urethral mucosa from friction. When performing the endoscopy, the device could act as a barrier between urethral mucosa and the endoscope. Moreover, in the situation of encountering difficulties in catheterization, the sheath could also be used as a guide-wire to lead the catheter through its lumen course. Thus, it is proposed that this radially expanding sheath could be a potential powerful approach for reducing the risks and complications of urethral dilation.