Accumulating evidence implicates the transmission of α-synuclein within the brain as an alternate route for the pathogenesis of Parkinson’s disease (PD). However, little is known about the initial cellular event(s) that result in the propagation of pathology associated with PD. Defining this molecular event is of fundamental importance, as it would allow for the targeting of α-synuclein transmission before the irreversible spreading of protein pathology occurs. We have identified a mechanistic pathway for the exosomal release of alpha-synuclein mediated by a protein called Ndfip1. Ndfip1 is upregulated in response to stress, including metal dysregulation and lysosomal failure, both of which have been linked to PD onset. Importantly, we have previously reported the upregulation of Ndfip1 in response to increased iron in PD brains. Here we show that Ndfip1 can directly interact and mediate the ubiquitination of α-synuclein, resulting in the activation of an endosomal pathway that leads to the exosomal release of α-synuclein from the cell. We demonstrate that exosomal α-synuclein can be transmitted to recipient cells indicating a pathway for the transmission of α-synuclein from cell to cell. These findings highlight a mechanism were α-synuclein can be transmitted within the brain through an exosome dependent pathway.