Patients with idiopathic Parkinson's disease (IPD) are described as having markedly decreased novelty seeking characteristics. Since recent publications suggest an association between the dopamine D4 receptor polymorphism and novelty seeking, we investigated this polymorphism in a group of 122 patients with IPD and 127 healthy control subjects. We found similar allele and genotype frequencies in both groups and no association with the age of onset of symptoms. Therefore, the dopamine D4 receptor polymorphism does not confer genetic susceptibility to IPD and cannot explain the decreased novelty seeking in IPD patients.