OBJECTIVE: To evaluate the direct costs due to Parkinson's Disease (PD) in Germany. METHODS: Using a prospective study design we evaluate the health care utilization and health-related quality of life of 160 patients with PD in different Hoehn and Yahr stages (HY) over a two year period in Germany (2000-2002). Here we present a subanalysis of consecutive 34 patients (mean age: 65.2 ± 10.5) observed for a three-month period. Costs were derived from different German medical economic resources and determined from the perspective of the health care provider. RESULTS: The mean 3-month direct costs were DM 11300. DM 10000 were caused by medical treatment and DM 1300 by non-medical services (e.g. social services, meels on wheels, etc.). The drug costs were the major cost-factor with DM 8940, mainly caused by the use of newer compounds like dopamine agonists and COMT-inhibitors. The use of subcutaneous apomorphine in advanced stages of the disease considerably increased the costs of treatment (DM 6400). Hospitalisation, physician care and vindication amounted to DM 1060. Direct costs increased depending on the extent of the disease (HY I: DM 2080, HY V: DM 8840). Further cost driving factors include the occurrence of dyskinesias and motor fluctuations. Especially, the drug and hospitalisation costs are influenced by the occurrence of motor complications. CONCLUSIONS: Similar to earlier studies (Dodel et al., 1995) an increase in costs was calculated depending on HY stage and the occurrence of motor complications. Compared to the medical costs, the non medical services contribute only in a small proportion to the overall direct costs. The major cost factor is the drug treatment of Parkinson's disease. The greatest proportion of these costs is caused by drugs introduced in the last five years.