This chapter focuses on the propagation of vortex beams inside a GRIN medium. After an overview in Section 8.1 of polarization-related topics such as the Stokes vector and the Poincare sphere, the concept of a phase singularity is discussed in Section 8.2. This concept is used to form specific combinations of the modes that act as vortices with different state of polarizations. In Section 8.3, we discuss the techniques used for generating different types of vortex beams. Section 8.4 shows that a vortex beam also exhibits the self-imaging property during its propagation inside a GRIN medium. The impact of random mode coupling is also discussed in this section. Vortex-based applications of GRIN fibers are covered in Section 8.5.