Objective: To determine if a polymorphism of the dopamine D3 receptor gene (2 allele), which has been reported previously to be associated with polycystic ovary syndrome (PCOS) in a population of United States Hispanic women, is associated with the disorder in the southeastern United States. Design: Prospective case-control study. Setting: University reproductive endocrinology laboratory and outpatient clinic. Patient(s): Consecutive patients of non-Hispanic white race diagnosed with PCOS (n = 152) and healthy controls (n = 96). Intervention(s): None. Main Outcome Measure(s): Patient and control dopamine D3 receptor genotypes, with the 1 allele representing the wild type and the 2 allele denoting a highly prevalent polymorphism. Result(s): No difference was noted in the distribution of the three dopamine D3 receptor genotypes (i.e., 1:1, 1:2, and 2:2) among PCOS patients as compared with controls. Furthermore, in contrast to a previous report, the 2:2 genotype was not more prevalent among PCOS patients than among controls. Conclusion(s): Our population of non-Hispanic white women from the southeastern United States did not demonstrate an association between a dopamine D3 receptor polymorphism and PCOS.