Variants in the dopamine receptor D3 (DRD3) and HCLS1 binding protein 3 (HS1BP3) have been nominated as risk factors for essential tremor (ET). Although ET and Parkinson disease (PD) are considered different entities, they have many overlapping clinical and pathological features. We aim to evaluate the role of the Ser9Gly variant in DRD3 and Ala265Gly in HS1BP3 in PD development. To this end, we genotyped these two variants in a PD matched case-control series from the United States. Statistical analysis failed to identify significant differences in the frequency of these variants between the case and control groups; therefore our results do not support a role for these DRD3 and HS1BP3 variants in PD.