The role of the venous circulation has long been underestimated in clinical practice and in research into neurological diseases. In this review, we present an overview of the existing evidence that venous abnormalities can play a key role in the development and manifestation of neurological and neurodegenerative diseases. We review the history behind the role of venous diseases in multiple sclerosis and their connections with the disease landmarks, the links of chronic venous hypertension to cerebral hydrodynamics and the role of iron in MS. In addition, we highlight the role of venous abnormalities in other diseases including jugular venous reflux, developmental anomalies, hydrocephalus and cerebrospinal fluid flow. Finally, and based on the information presented throughout the whole review, we conclude with the link between chronic cerebrospinal venous insufficiency and MS and the role and power of magnetic resonance imaging in diagnosing venous anomalies.