Normal function of the dopaminergic system is necessary for speech fluency. There was evidence that the activities of dopamine transporter (DAT) and dopamine D2 receptor (DRD2) could be altered in people with speech disfluency. This study aims to ascertain the possible correlation between two dopaminergic genes (SLC6A3 and DRD2) and disorder of speech fluency, and to determine the allelic frequencies of the five single-nucleotide polymorphisms (SNPs) (rs2617604, rs28364997, rs28364998 in SLC6A3 and rs6275, rs6277 in DRD2) among Han Chinese patients with this disorder. A sample of 112 patients with speech disfluency and 112 gender-matched controls were included in this case-control study. The results show that the presence of C allele at rs6277 in DRD2 gene is associated with increased susceptibility to the disorder, whereas T allele is protective. Haplotype 939T/957T is also a protective factor.