The authors investigated the association between dopamine receptor D2, D3 gene polymorphisms, and the risk of developing motor fluctuations in PD. DRD3 BalI and MspI polymorphisms were not associated with risk of developing motor fluctuations. However, the genotypic distribution of DRD2 TaqIA polymorphism was significantly different in motor fluctuators and nonmotor fluctuators. These findings suggest that DRD2 TaqIA polymorphism may be associated with an increased risk for developing motor fluctuations in PD.