Although iron plays an important role in many aspects of human neurophysiology, it also can be toxic under certain circumstances. Anomalous amounts of iron are known to be associated with most types of neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's diseases. To date, little is known about the specific iron compounds present in this tissue and there is recent evidence to suggest that some forms are magnetic. This raises important questions with regard to the role of magnetic iron compounds in disease initiation and progression and, indeed, the origin of these compounds. This paper reviews recent work on the identification and analysis of magnetic iron compounds associated with neurological disorders.