Prion-propagating cell lines are an efficient and useful means for studying the cellular and molecular mechanisms implicated in prion disease. Use of cell-based models has lead to the finding that prion protein (PrP(C)) and PrP(Sc) are released from cells in association with exosomes. Furthermore, exosomes have been shown to act as vehicles for infectivity, transferring PrP(Sc) between cell lines and providing a mechanism for prion spread between tissues. As a role for exosomes in prion disease is emerging, this chapter outlines a method for the generation of prion-infected cell lines and the isolation and characterization of PrP(C)- and PrP(Sc)-containing exosomes.