Iron content of the basal ganglia was investigated in 25 patients with idiopathic Parkinson's disease and 14 matched healthy control subjects using a partially refocused interleaved multiple echo sequence on a 1.5 Tesla MRI system. R₂* (1/T₂*) and R₂′ (1/T₂′) relaxation rates were higher in the substantia nigra of patients with Parkinson's disease, which indicates that iron content is elevated in this region. R₂′ was lower in the putamen, indicating reduced iron levels; reduction in this region was positively correlated with disease duration. Iron-related oxidative stress may contribute to the neurodegeneration of Parkinson's disease, which may lead to alterations in the iron levels of the striatum. We describe a simple, non-invasive technique for measuring iron content.