We compared CSF and serum levels of iron, copper, manganese, and zinc, measured by atomic absorption spectrophotometry, in 37 patients with Parkinson's disease (PD) and 37 matched controls. The CSF levels of zinc were significantly decreased in PD patients as compared with controls (p < 0.05). The serum levels of zinc, and the CSF and serum levels of iron, copper, and manganese, did not differ significantly between PD-patient and control groups. There was no influence of antiparkinsonian therapy on CSF levels of none of these transition metals. These values were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale of the Hoehn and Yahr staging in the PD group, with the exception of CSF copper levels with the duration of the disease (r = 0.38, p < 0.05). These results suggest that low CSF zinc concentrations might be related with the risk for PD, although they could be related with oxidative stress processes.