Parkinson’s Disease is characterized by the degeneration of neuromelanin (NM)-containing neurons in the Substantia Nigra (SN). MRI techniques have emerged aiming to evaluate PD disease progression. NM-MRI (current gold-standard), depicts a reduction in signal intensity at the posterior SN. Recently, free water (FW) fraction maps obtained from DWI, have shown an increase of FW in the SN in PD. This work’s goal was to evaluate how the FW and NM signal relate. A negative correlation between FW and NM was observed in the SN posterior region, suggesting that both metrics can potentially be used as imaging biomarkers.